Pull Request for Dual Head Support in Mednafen

Changes in xbmc:

different icons for native and RetroRig mode (#61)
passing down display settings (#58)
clean up debug messages
Stay fullscreen after game launch (#68)
Debian packaging control file for RetroRig
Splash screen for RetroRig

Changes in mednafen:

changed to SDL2 (experimental!!)
dual head support (#58)
Debian packaging contol file for RetroRig
new build script

Changes in RetroRig:
`wget --tries=50 libregeek.org` for all wget's

Tested thoroughly on several scratch installations.