PETSc 3.5.1 with intel 2014b

Plus dependencies
Needs https://github.com/hpcugent/easybuild-easyblocks/pull/446
and https://github.com/hpcugent/easybuild-framework/pull/987


@wpoely86: we can't change the existing template URL without breaking backward compatibility; we can define a new one with a slightly different name though (e.g., `..._BIS`)