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
Miscellaneous DiracKernel improvements

* Storing a vector<Point> per Elem rather than a set<Point> for
  DiracKernels.  A std::set<Point> is always somewhat dangerous due to
  the floating point nature of operator< for Points.
* The DiracKernel object now uses two DiracKernelInfo objects to avoid duplicating code.
* Give DiracKernelInfo a more standard interface since it is used in a few more places now...
* Adding DiracKernel::hasPoint()
* Implement DiracKernelInfo::addPoint() in terms of DiracKernelInfo::hasPoint()
* Adding documentation.

Refs #2847.
Merge pull request #3095 from jwpeterson/dirac_set

Miscellaneous DiracKernel improvements
Merge pull request #3091 from permcody/default_values_final

Finishing up default value work
Separating NeighborCoupleable into its own file (closes #3110)
Merge pull request #3111 from andrsd/3110

Separating NeighborCoupleable into its own file (closes #3110)