[Opm] Renaming dune-cornerpoint -> opm-grid

[Atgeirr Rasmussen]

Dear OPM community,

We have now completed renaming dune-cornerpoint -> opm-grid. Now the module name is changed throughout the system.

1. If you have not already done so, you should now rename your github fork (if you have one) from dune-cornerpoint to opm-grid.

2. You should rename your dune-cornerpoint working directory to opm-grid.

3. You should look at the remote URLs used in that directory with "git remote -v" and check that they refer to the
correct URL (opm-grid.git, not dune-cornerpoint.git). If not use "git remote set-url" to update (replace dune-cornerpoint with opm-grid).

4. You should pull down the changes in all repositories (including opm-grid). The repositories changed for this renaming include
opm-common, opm-core, opm-grid, opm-autodiff, opm-upscaling and ewoms.

5. In each build directory, I recommend deleting all files and doing the "cmake <location of source>" command again.

6. Do 'make' in each build directory.

You should (hopefully) have no problems. If you do, please report and we'll try to fix it.

Atgeirr