Fix youtu.be regex so it supports capital letters and properly escapes hyphens.
Use protocol-relative URLs.
Fixed so the editor renders in XHTML mode apparently some people still use this rendering mode.
Merge pull request #347 from Kindling/patch-media-regex

Fix media plugin regexes and use protocol-relative URIs.
Fixed minor issue in saucelabs.js.
Updated icons to match the latest icomoon format and enabled -moz-osx-font-smoothing on FF Mac OS X.