Convert libmesh_cast_{ptr,ref} -> cast_{ptr,ref}

Refs #3737.
libMesh update.  Refs #000.
Add Executioner::terminate() (#3735)
Add Terminator UserObject (#3735)
Deduce needed postprocessors (#3735)
move logic from Executioner into Problem (#3735)
Move Terminator UO into core, new test (#3735)
fix missing initializer (#3735)
Simplify test, fix "teh" (#3735)
make test non-random (#3735)
Merge pull request #3739 from dschwen/terminate_3735

Terminate solves cleanly based on Postprocessor values
Merge pull request #3738 from jwpeterson/libmesh_cast

Convert libmesh_cast_{ptr,ref} -> cast_{ptr,ref}
Disable test in recover mode (#3735)
Reenable and set num_steps to 6 (#3735)
Merge pull request #3760 from dschwen/terminate_3735

Fix test in recover mode
Merge commit 'a0b81f16ec666f8c4c5081cb4003e8b1332a028f'