Implement multi-region PVT tables
Added function grid_equal() to compare two UnstructuredGrid instances.
Renamed struct EclipseGrid -> struct EclipseWriterGrid to avoid conflict
with class in opm-parser.
ERT-601: Added GridManager() constructor which takes a Parser::EclipseGrid instance
Changed the data files used for testing:

1) Added RUNSPEC section
2) Replaces DEPTHZ keyword with TOPS keyword.
convert the EclipseGridInspector to opm-parser

that one is completely unused in opm-core (*booo*!), but used quite a
bit in dune-cornerpoint and dune-porsol, so let's keep it for now...
CornerPointChopper: add methods opm-parser'y methods
add opm-parser variants for the incompressible property classes
remove the import_rewrite example

that one was quite specific to the old parser and would thus require
more work to convert to the opm-parser than what it is worth the
effort. If you _really_ want to keep this tool, ping me and I'll port
it...
convert the examples and the tests to opm-parser