Support a local.mk file

This allows for variables to be set in one place for local setups (paths
to paraview, netcdf, options, etc.)
Use DataDescriptions for different mesh types
Add separate data streams for primary and dual meshes
Fix an off-by-one in XY_NLayer.cxx
Register a timestep with catalyst
Flip around inverted dual grid cells
Store cell masks in a map

This allows the different outputs to use their own flags for whether a
cell is useful or not rather than stomping on each other.
Flip backwards triangles as well
Remove custom VTK writing function

The Catalyst Python script now controls this.