HAML Mode for Coda 2

To install this mode:

1. Download this repo as a ZIP
2. Rename the folder that's generated to "haml.mode"
3. Move the folder to ~/Library/Application Support/Coda 2/Modes

This was originally adapted from https://github.com/gf3/haml.mode, but most or all of that code was pulled out. Inline Ruby stuff was pulled from Panic's ERB mode, and altered to suit.