Build modified streamline images

The official image from streamline does not currently work for the arm64
platform. As a temporary measure, the source code and docker build scripts
have been lifted from the official images and are used to build locally.

Some additional modifications are made to reduce overall image size, these
are documented in docker/README.md

docker/streamline-src/public/elite/bootstrap/less/mixins/vendor-prefixes.less

@@ -0,0 +1,227 @@
+// Vendor Prefixes
+//
+// All vendor mixins are deprecated as of v3.2.0 due to the introduction of
+// Autoprefixer in our Gruntfile. They have been removed in v4.
+
+// - Animations
+// - Backface visibility
+// - Box shadow
+// - Box sizing
+// - Content columns
+// - Hyphens
+// - Placeholder text
+// - Transformations
+// - Transitions
+// - User Select
+
+
+// Animations
+.animation(@animation) {
+  -webkit-animation: @animation;
+       -o-animation: @animation;
+          animation: @animation;
+}
+.animation-name(@name) {
+  -webkit-animation-name: @name;
+          animation-name: @name;
+}
+.animation-duration(@duration) {
+  -webkit-animation-duration: @duration;
+          animation-duration: @duration;
+}
+.animation-timing-function(@timing-function) {
+  -webkit-animation-timing-function: @timing-function;
+          animation-timing-function: @timing-function;
+}
+.animation-delay(@delay) {
+  -webkit-animation-delay: @delay;
+          animation-delay: @delay;
+}
+.animation-iteration-count(@iteration-count) {
+  -webkit-animation-iteration-count: @iteration-count;
+          animation-iteration-count: @iteration-count;
+}
+.animation-direction(@direction) {
+  -webkit-animation-direction: @direction;
+          animation-direction: @direction;
+}
+.animation-fill-mode(@fill-mode) {
+  -webkit-animation-fill-mode: @fill-mode;
+          animation-fill-mode: @fill-mode;
+}
+
+// Backface visibility
+// Prevent browsers from flickering when using CSS 3D transforms.
+// Default value is `visible`, but can be changed to `hidden`
+
+.backface-visibility(@visibility) {
+  -webkit-backface-visibility: @visibility;
+     -moz-backface-visibility: @visibility;
+          backface-visibility: @visibility;
+}
+
+// Drop shadows
+//
+// Note: Deprecated `.box-shadow()` as of v3.1.0 since all of Bootstrap's
+// supported browsers that have box shadow capabilities now support it.
+
+.box-shadow(@shadow) {
+  -webkit-box-shadow: @shadow; // iOS <4.3 & Android <4.1
+          box-shadow: @shadow;
+}
+
+// Box sizing
+.box-sizing(@boxmodel) {
+  -webkit-box-sizing: @boxmodel;
+     -moz-box-sizing: @boxmodel;
+          box-sizing: @boxmodel;
+}
+
+// CSS3 Content Columns
+.content-columns(@column-count; @column-gap: @grid-gutter-width) {
+  -webkit-column-count: @column-count;
+     -moz-column-count: @column-count;
+          column-count: @column-count;
+  -webkit-column-gap: @column-gap;
+     -moz-column-gap: @column-gap;
+          column-gap: @column-gap;
+}
+
+// Optional hyphenation
+.hyphens(@mode: auto) {
+  word-wrap: break-word;
+  -webkit-hyphens: @mode;
+     -moz-hyphens: @mode;
+      -ms-hyphens: @mode; // IE10+
+       -o-hyphens: @mode;
+          hyphens: @mode;
+}
+
+// Placeholder text
+.placeholder(@color: @input-color-placeholder) {
+  // Firefox
+  &::-moz-placeholder {
+    color: @color;
+    opacity: 1; // Override Firefox's unusual default opacity; see https://github.com/twbs/bootstrap/pull/11526
+  }
+  &:-ms-input-placeholder { color: @color; } // Internet Explorer 10+
+  &::-webkit-input-placeholder  { color: @color; } // Safari and Chrome
+}
+
+// Transformations
+.scale(@ratio) {
+  -webkit-transform: scale(@ratio);
+      -ms-transform: scale(@ratio); // IE9 only
+       -o-transform: scale(@ratio);
+          transform: scale(@ratio);
+}
+.scale(@ratioX; @ratioY) {
+  -webkit-transform: scale(@ratioX, @ratioY);
+      -ms-transform: scale(@ratioX, @ratioY); // IE9 only
+       -o-transform: scale(@ratioX, @ratioY);
+          transform: scale(@ratioX, @ratioY);
+}
+.scaleX(@ratio) {
+  -webkit-transform: scaleX(@ratio);
+      -ms-transform: scaleX(@ratio); // IE9 only
+       -o-transform: scaleX(@ratio);
+          transform: scaleX(@ratio);
+}
+.scaleY(@ratio) {
+  -webkit-transform: scaleY(@ratio);
+      -ms-transform: scaleY(@ratio); // IE9 only
+       -o-transform: scaleY(@ratio);
+          transform: scaleY(@ratio);
+}
+.skew(@x; @y) {
+  -webkit-transform: skewX(@x) skewY(@y);
+      -ms-transform: skewX(@x) skewY(@y); // See https://github.com/twbs/bootstrap/issues/4885; IE9+
+       -o-transform: skewX(@x) skewY(@y);
+          transform: skewX(@x) skewY(@y);
+}
+.translate(@x; @y) {
+  -webkit-transform: translate(@x, @y);
+      -ms-transform: translate(@x, @y); // IE9 only
+       -o-transform: translate(@x, @y);
+          transform: translate(@x, @y);
+}
+.translate3d(@x; @y; @z) {
+  -webkit-transform: translate3d(@x, @y, @z);
+          transform: translate3d(@x, @y, @z);
+}
+.rotate(@degrees) {
+  -webkit-transform: rotate(@degrees);
+      -ms-transform: rotate(@degrees); // IE9 only
+       -o-transform: rotate(@degrees);
+          transform: rotate(@degrees);
+}
+.rotateX(@degrees) {
+  -webkit-transform: rotateX(@degrees);
+      -ms-transform: rotateX(@degrees); // IE9 only
+       -o-transform: rotateX(@degrees);
+          transform: rotateX(@degrees);
+}
+.rotateY(@degrees) {
+  -webkit-transform: rotateY(@degrees);
+      -ms-transform: rotateY(@degrees); // IE9 only
+       -o-transform: rotateY(@degrees);
+          transform: rotateY(@degrees);
+}
+.perspective(@perspective) {
+  -webkit-perspective: @perspective;
+     -moz-perspective: @perspective;
+          perspective: @perspective;
+}
+.perspective-origin(@perspective) {
+  -webkit-perspective-origin: @perspective;
+     -moz-perspective-origin: @perspective;
+          perspective-origin: @perspective;
+}
+.transform-origin(@origin) {
+  -webkit-transform-origin: @origin;
+     -moz-transform-origin: @origin;
+      -ms-transform-origin: @origin; // IE9 only
+          transform-origin: @origin;
+}
+
+
+// Transitions
+
+.transition(@transition) {
+  -webkit-transition: @transition;
+       -o-transition: @transition;
+          transition: @transition;
+}
+.transition-property(@transition-property) {
+  -webkit-transition-property: @transition-property;
+          transition-property: @transition-property;
+}
+.transition-delay(@transition-delay) {
+  -webkit-transition-delay: @transition-delay;
+          transition-delay: @transition-delay;
+}
+.transition-duration(@transition-duration) {
+  -webkit-transition-duration: @transition-duration;
+          transition-duration: @transition-duration;
+}
+.transition-timing-function(@timing-function) {
+  -webkit-transition-timing-function: @timing-function;
+          transition-timing-function: @timing-function;
+}
+.transition-transform(@transition) {
+  -webkit-transition: -webkit-transform @transition;
+     -moz-transition: -moz-transform @transition;
+       -o-transition: -o-transform @transition;
+          transition: transform @transition;
+}
+
+
+// User select
+// For selecting text on the page
+
+.user-select(@select) {
+  -webkit-user-select: @select;
+     -moz-user-select: @select;
+      -ms-user-select: @select; // IE10+
+          user-select: @select;
+}