Restore font-preloaders for Google Fonts

Needed because the "gear help bubble" (which preloaded Google Fonts)
has been removed
Move JS files into new directory structure
Move switchery UI code to new JS files
Move support panel UI code to new JS file
Move help UI code to new JS file
Fix JSHint warnings
Grunt: create package.json for NPM
Grunt: create .gitignore for node_modules
Grunt: create Gruntfile.js
Grunt: create minified JS files
Grunt: use minified JS files