Pull request for upgrade to pl4

Tested on a scratch Ubuntu install:

 - build-xbmc.sh runs flawless
 - icon from RetroRig now very nice http://i.imgur.com/BSYoWnq.jpg #61
 - no hanging upon exit #45
 - no broken play button #45
 - dual-head super nice
 - XBMC and RetroRig running alongside with each other #31 

Awesome!

When you are done with disabling service xbmc.versioncheck in the config files, you can uncomment the lines here: https://github.com/beaumanvienna/RetroRig/blob/beta/supplimental/build-xbmc.sh#L159

Patch files for pl3 and pl4 are provide here (just for reference): https://github.com/beaumanvienna/RetroRig/tree/beta/XBMC-cfgs/extra/patches

Like talked earlier, the RetroRig icon is now installed in a proper location. You might want to consider changing the desktop starter files.

xbmc.bin corresponds to what I send you yesterday plus the icon fix. So lot's of debug messages!

We can test all this for a while and then close #45 and #61.

Great job!

[EDIT]:
I also tested mednafen-0.9.36.2-SDL2-dual-head on my scratch system. It runs flawless.
It would be really cool, if you could give this a try. Just to see if you notice any difference to our current version... Here are some installation instructions, it's pretty easy:

https://github.com/beaumanvienna/mednafen-git/blob/mednafen-0.9.36.2-SDL2-dual-head/instructions.txt