Search for patch file in directory of the easyconfig file

If you use a easyconfig outside of the python tree and there
is a patch file in the directory of the easyconfig, easybuild
will find it.
Remove temp git directory

Currently, /tmp fills up with empty /tmp/git-wc-* directories. This
commit makes sure that this directory is also removed.
Merge pull request #667 from wpoely86/develop

Search for patch file in directory of the easyconfig file