Added rough test for some issues with Navier Stokes local conservation.
Merge branch 'master' of github.com:CamelliaDPG/Camellia
Merge branch 'master' of github.com:CamelliaDPG/Camellia

Conflicts:
	drivers/DPGTests/IncompressibleFormulationsTests.cpp
Merged IncompressibleFormulationsTests to include both versions of an effort looking into what's wrong with locally conservative Navier-Stokes.  These are fairly redundant, and one should be eliminated.
Added png output to various GnuPlotUtil script generators.
Commented out the png output commands from the generated gnuplot scripts--having trouble adding png support to my copy of gnuplot.