extract raw-files.js generator out of Gruntfile into separate module

docs/grunt/bs-raw-files-generator.js

@@ -0,0 +1,22 @@
+/* jshint node: true */
+
+var btoa = require('btoa')
+var fs = require('fs')
+
+function getFiles(type) {
+  var files = {}
+  fs.readdirSync(type)
+    .filter(function (path) {
+      return type == 'fonts' ? true : new RegExp('\\.' + type + '$').test(path)
+    })
+    .forEach(function (path) {
+      var fullPath = type + '/' + path
+      return files[path] = (type == 'fonts' ? btoa(fs.readFileSync(fullPath)) : fs.readFileSync(fullPath, 'utf8'))
+    })
+  return 'var __' + type + ' = ' + JSON.stringify(files) + '\n'
+}
+
+module.exports = function generateRawFilesJs() {
+  var files = getFiles('js') + getFiles('less') + getFiles('fonts')
+  fs.writeFileSync('docs/assets/js/raw-files.js', files)
+}