fix tslib integration

As seen in many threads there is a long lasting issue with touchscreens. Even when working perfectly in any X window manager and through TSLIB is seems to remain an issue when trying to use on an standalone running xbmc.

Several examples of threads discussing this:

http://forum.xbmc.org/showthread.php?tid=129299
http://forum.xbmc.org/showthread.php?tid=141358
http://forum.xbmc.org/showthread.php?tid=89536
http://forum.xbmc.org/showthread.php?tid=84008
And there are several topics on plenty of other forums.

My own detailed description on the issue:
http://forum.xbmc.org/showthread.php?tid=162538


I truly believe this to be a core-xbmc issue as I have been trying for a couple of weeks already on several linux flavours (Debian, Ubuntu, Arch, Linux Mint, Raspbian, OpenELEC, etc...) and several custom build solutions and tutorials out there all with the same result.

So, if this could please be considered I'm sure a lot of touchscreen users out there will greatly appreciate.

PS: although I'm not a developer, please do reach out to me if I can help in any way.