Set abs_zero for adv_diff_test
closes #3730
Fixed valgrind error, flush it
(closes #3710)
Merge pull request #3721 from aeslaughter/valgrind-3710

Fixed valgrind error
Merge pull request #3733 from permcody/adv_diff

Set abs_zero for adv_diff_reaction_test
ActionWarehouse holds a MooseSharedPointer<MooseMesh> instead of a MooseMesh*

It provides access to other parts of the code, like
SetupMeshAction:act() and MooseApp::meshOnly(), that are actually
responsible for constructing the Mesh object.  This means that other
objects, like FEProblem, are no longer responsible for deleting the
Mesh.

See also #3446
Adding some valgrind suppressions for openmpi

Refs #3547
Same thing for the DisplacedMesh owned by ActionWarehouse