Integrate crash handler from compiz-plugins-extra into Compiz

[berylline]

There's no good reason for the crash handler to remain separate from the Compiz project itself. Not sure why the original Compiz authors did it this way. siiiggghh.... Anyway...

Integrate the crash handler into the main Compiz code itself so as to have Compiz provide some info on why it crashed when it does.

Crash handler code here for reference:

https://github.com/berylline/compiz-plugins-extra/blob/master/src/crashhandler/crashhandler.c