better gcc support for mac

Conflicts:
	easybuild/easyblocks/g/gcc.py

Releasing v0.8

Now we move easybuild (former easybuild.sh) to eb and we keep the
easybuild directory in place (instead of in lib/)

Inside the __init__.py file in lib/ we change the sys.path variable to
include the easybuild directory. This way, no special import changes
have to be made.

config.guess is a script which is also run by gcc during configuring.
On a mac uname does not provide the correct build target

Merge branch '1226_MrBayes' of ssh://gengar.ugent.be/user/home/gent/vsc400/vsc40003/easybuild_git_branches/ageorges into 1226_MrBayes