Use updated MooseMesh/libMesh interfaces.
Use updated MooseMesh/libMesh interfaces.

Refs idaholab/moose#6929.

andrsd/moose,lindsayad/moose,dschwen/moose,milljm/moose,jessecarterMOOSE/moose,bwspenc/moose,sapitts/moose,idaholab/moose,harterj/moose,jessecarterMOOSE/moose,sapitts/moose,milljm/moose,andrsd/moose,jessecarterMOOSE/moose,laagesen/moose,lindsayad/moose,andrsd/moose,harterj/moose,lindsayad/moose,andrsd/moose,dschwen/moose,milljm/moose,jessecarterMOOSE/moose,bwspenc/moose,harterj/moose,lindsayad/moose,bwspenc/moose,milljm/moose,dschwen/moose,sapitts/moose,lindsayad/moose,harterj/moose,laagesen/moose,idaholab/moose,sapitts/moose,harterj/moose,bwspenc/moose,jessecarterMOOSE/moose,andrsd/moose,laagesen/moose,dschwen/moose,laagesen/moose,laagesen/moose,milljm/moose,idaholab/moose,idaholab/moose,sapitts/moose,dschwen/moose,bwspenc/moose,idaholab/moose