Finishing up default value work
-Modifying test to demonstrate that ParsedFunctions or ConstantFunctions can be used where FunctionName parameters are requested.
closes #3047
Fixing up HeatSource in modules (inherits from BodyForce)
refs #3047
Merge pull request #3091 from permcody/default_values_final

Finishing up default value work
Merge commit 'd43bd3c5b2763e1ca400bf60203d198075b3178a'