Fix bgrp>1 without ACE
Fix issue #42 (closed) case 2. Both k and gamma code paths are fixed. Removed no more needed and buggy exxbuff_comm and exxbuff_comm_gamma.
Fix issue #42 (closed) case 2. Both k and gamma code paths are fixed. Removed no more needed and buggy exxbuff_comm and exxbuff_comm_gamma.