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/grunt/bs-glyphicons-data-generator.js

@@ -0,0 +1,42 @@
+/*!
+ * Bootstrap Grunt task for Glyphicons data generation
+ * http://getbootstrap.com
+ * Copyright 2014-2015 Twitter, Inc.
+ * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
+ */
+
+'use strict';
+
+var fs = require('fs');
+
+module.exports = function generateGlyphiconsData(grunt) {
+  // Pass encoding, utf8, so `readFileSync` will return a string instead of a
+  // buffer
+  var glyphiconsFile = fs.readFileSync('less/glyphicons.less', 'utf8');
+  var glyphiconsLines = glyphiconsFile.split('\n');
+
+  // Use any line that starts with ".glyphicon-" and capture the class name
+  var iconClassName = /^\.(glyphicon-[a-zA-Z0-9-]+)/;
+  var glyphiconsData = '# This file is generated via Grunt task. **Do not edit directly.**\n' +
+                       '# See the \'build-glyphicons-data\' task in Gruntfile.js.\n\n';
+  var glyphiconsYml = 'docs/_data/glyphicons.yml';
+  for (var i = 0, len = glyphiconsLines.length; i < len; i++) {
+    var match = glyphiconsLines[i].match(iconClassName);
+
+    if (match !== null) {
+      glyphiconsData += '- ' + match[1] + '\n';
+    }
+  }
+
+  // Create the `_data` directory if it doesn't already exist
+  if (!fs.existsSync('docs/_data')) {
+    fs.mkdirSync('docs/_data');
+  }
+
+  try {
+    fs.writeFileSync(glyphiconsYml, glyphiconsData);
+  } catch (err) {
+    grunt.fail.warn(err);
+  }
+  grunt.log.writeln('File ' + glyphiconsYml.cyan + ' created.');
+};