Add the processor architecture to the topology signature

Conflicts:
	opal/mca/hwloc/base/hwloc_base_util.c
Restore full topology comparison to support inventory monitoring

Conflicts:
	opal/mca/hwloc/base/hwloc_base_dt.c
Automatically detect hetero node situations

Cherry-pick plus cleanup of:

open-mpi@bb529eb
open-mpi@9b2f8cd
open-mpi@18d9fdf
Merge pull request #112 from rhc54/cmr/hetero-nodes

Add automatic detection of hetero nodes