SideSetsAroundSubdomain runs with ParallelMesh.

The algorithm doesn't use flood().

Refs #2129.
Merge pull request #3139 from jwpeterson/sidesets_around_subdomain

SideSetsAroundSubdomain should work with ParallelMesh
Removing AuxBCs
(closes #3021)
Removed [AuxBCs] from modules
(#3021)
Allow ability to use AuxBCs block
(#3021)
Revert this commit to remove the AuxBCs block