Treat mpi_family MPICH as MPICH 3.x instead of MPICH 1.x
Fix handling of MPICH 3.x for Scalasca 1.4.3

For Scalasca 1.x, there /is/ actually a difference between MPICH2 and
MPICH 3.x. The latter is only supported since Scalasca 1.4.3 (older
versions won't compile) and now correctly selected by the easyblock.
fix use of mpi_family() in ALADIN, Intel MKL and NWChem easyblocks, w.r.t. MPICH family
use 'mpich2' value for ESMF_COMM with MPICH family (i.e., MPICH v3.x)
Fix typo
Merge pull request #519 from geimer/fix_mpich_inconsistencies

Treat mpi_family MPICH as MPICH 3.x instead of MPICH 1.x