Split YaspGrid tests into more tests and introduce parallel testing

The previous YaspGrid test was a single test which took ages to compile and run.

This branch remodels the Yasp testing suite to achieve the following:

• Split the different parts into separate tests
• Introduce a more sophisticated communication test
• Test periodic grids
• Do parallel testing through dune_add_test
• Test with -Wall -Werror!!!
• Have tests with and without deprecations!