add Roland's dune version detection magic from OPM core

(this commit should be removed as soon as the cmake rollup is complete.)
convince cmake to use UseDuneVer

this is also only temporary until the big rollup completes
make it compile without warning on the DUNE git master

the biggest issue was that they removed the 'Allocator' template
argument from 'Dune::PersistentContainer'.
Merge pull request #42 from andlaus/dune23

make it compile on dune 2.3