08.Commit:	adapted baseline_impl to the new interface and minor changes to interface
greschd

DONE:
- adapted baseline_impl_greschd to match the interface
- changed baseline_impl_greschd to 3D
- changed the folder structure and added cmake files
- moved the implementations not matching the interface to folder old/
- wrapped std::mt19937 to match the rng interface

TODO:
- write a testing environment validating/comparing different implementations
Merge branch 'master' of github.com:OptimalCoders/mc_potts
09.Commit:	fixed bug in baseline_impl_greschd, addressing comment
greschd

DONE:
- fixed baseline_impl_greschd
- added a picture_slice to baseline_impl_greschd
- restructured according to comment on 08.Commit