subtitles proof of concept (Hacky)

Need some answers from lead developers to questions such as:

* "how to fit this in with the existing yaml?"
* "to what extent should messages be reported in text? And should there be groups of voices to enable?"
* "make sure announcements like the commando laugh, cloak activate and superpower warnings are narrated."
* "is this to be shared with the existing chat dialog?"

Added some random subtitles to the RA mod to show.
![arf](https://cloud.githubusercontent.com/assets/1812087/4100239/fa7c305e-3089-11e4-9786-811858e5b487.jpg)