convert the module away from EclipseGridParser to opm-parser
add possibility to use ad-hoc upscaling keywords

this is currently just "RHO", an non-standard addition for
opm-upscaling and needs to be added to the Eclipse parser manually
before it is set loose on the deck file...
cpchop example: fix indentation

at least for editors which use the "wrong" width for tabs. *grrr*
don't include files while inside a namespace

this leads to weird effects. We now close all namespace before
including the respective *_impl.hpp file and open the namespace within
the file itself. This allows to safely include headers within
the impl files...
fixed: dune ISTL 2.3 or newer

make workaround for bug in dune-istl < 2.3 conditional
Merge pull request #114 from akva2/fix_dune_2.3

fixed: dune ISTL 2.3 or newer
Merge pull request #113 from andlaus/move_to_opm-parser

Move to opm parser