Fixed handling of the boundary conditions for explicit solver - introduced a method Problem::applyBoundaryConditions.

Add StaticVectorFor - for cycle doing all combinations of directions

Heavy Refactorization of DistributedGrids:
	-> Reordered Directions
	-> Add some useless Direction helper functions
	-> Set Up DistributedGrid_Base - shared base with dim template parameter
	-> Add support for communicationGroup created for DistributedGrid (MPI communicator support)

Only MPICommunicator and DistributedGrid is implemented.

Allow existance of non setup synchronizer object. MeshFunction creates grid synchronizer automagicli with binding.
(only if distr grid was chnged)