Added distinct nonlinear convergence tolerance to VGP Navier-Stokes consistency check (distinct from tolerance used to determine success of test).  Also, added HDF5 output on failure.
Added missing equation to Stokes VGP formulation!  (The continuity equation / incompressibility constraint.)
Added getTraceDofIndices() method.
Added two tests against statically condensed solutions.
Added missing test variable (q, for the continuity equation) to StokesVGPFormulation.
Added methods to get/set stored load/stiffness for cell.  Important for zero-mean constraint imposition, which clobbers the load, and should restore it.
Added VarPtr accessors for several trial variables in VGPNavierStokesFormulation.
Added addFCs method to add two like-sized FieldContainers together, with optional weights.
Factored out setGlobalSolutionFromCellLocalCoefficients() method from initializeLHSVector(), fixed a bug in zero-mean constraint imposition for condensed solves, and changed addSolution() (one variant; still need to do the other) to play nicely with condensed solutions.
Restored imposition of zero-mean constraints, now that bugs are fixed.