Replace shallow copy with register call
Add vtkRasterFeature class

Only does simplistic/minimal scaling from lat-lon to map coordinates
Recast raster feature to use vtkRectilinear grid

To address nonlinear mapping of latitude to y coordinates
Also retool test program to generalize command-line arguments
Merge branch 'john/object-lifecycle-fixes' into databrowser
Merge branch 'john/add-raster-feature' into databrowser
Add line to set scalar range for color mapping