[oe] recipes/mesa cleanup

[Martin Jansa]

Hi,

i know the rules about removing old versions, but in this dir there were versions 
really old and I'm pretty sure they cant be even built with current OE (I tried in
few cases and then refused to spend whole day just to confirm that some 6.0 version 
still builds after converting to new staging and cleanups..).

Please review/test.

FYI: all those patches are often rebased on top of oe.dev also here 
http://gitorious.org/~jama/angstrom/jama-shr-experimental 
if cherry-picking is more effective way for you to test

Regards,