[common.crtp] added from dune-pymor * this defines CHECK_CRTP and CHECK_AND_CALL_CRTP   (has still to be made threadsafe perhaps?) * defines CRTPInterface
[common.crtp] added from dune-pymor
* this defines CHECK_CRTP and CHECK_AND_CALL_CRTP
  (has still to be made threadsafe perhaps?)
* defines CRTPInterface

renemilk/DUNE-Stuff,renemilk/DUNE-Stuff,renemilk/DUNE-Stuff