HipChat Web Xtras

Adds Xtra features to the HipChat web interface. Current Xtras Include...

- Custom HipChat web themes!

- Zen Mode (compose chat messages fullscreen w/ keyboard shortcuts).

- Tab Override (allows TAB key in message composition). Great for code samples.

- Automatic quoted replies in HipChat (just like GitHub). Select any text and press the `R` key for an automatic quoted reply in HipChat.

- Options panel integrated w/ HipChat. This allows you to pick and choose the HipChat Web Xtras you'd like to enable.