Conversion of PHPEPL to ACE editor 

I'm not sure if this is worth merging into the base path or having it as an alternate branch.

We've converted PHPepl to use the ACE editor instead of CodeMirror, as we like the aesthetics of ACE more than CodeMirror. There have also been some updates to composer, PHPSandbox, and some mild usage of Foundation.

Overall, we've made these changes  so the repl can be embedded more easily into other pages and articles throughout our websites.

You can see it in action [here](http://phpepl.sitepoint.com/).

We are looking to expand it in the future by allowing code blocks to be passed through to the repl or loaded from a code sample db, or perhaps even to be pulled in from github gists.

Comments welcome!