Add an option to provide compatibility feedback

Not sure these are the right fields or anything, but it can easily be changed.

report.ppsspp.org is updated to store this data already.  Probably should add a screenshot upload as well (might preview it on the report screen?)  Maybe comments.  Not sure anyone will want to type them on mobile, could just allow comments online if anywhere (disqus or something.)

Compatibility includes:
 * All reported config settings.
 * The game id (region and version.)
 * Version of the emulator.
 * Platform, cpu, and gpu (not on Direct3D 9 yet.)
 * The selected playability level and 3-star ratings for graphics, speed, and gameplay.

It *could* easily also include (being sent), but does not currently store:
 * The device screen resolution.
 * Game sdk version.
 * Recent average vps and fps.
 * Whether a savestate was loaded this play.

Anyway, we could correlate this information, by sending a request to the server.  It could ask for:
 * What ratings (speed, graphics, etc.) do people give for my device / devices with most similar attributes?
 * What settings have people rated the best compatibility for this game or game/device?

For example, I'm thinking the "Report Feedback" button could show stars or some icon to indicate how playable this game is.

-[Unknown]