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)

Code refactoring.

Only MPICommunicator and DistributedGrid is implemented.

For compatibility with unported examples, the old typedef is still kept,
but IndexType should be removed from grids eventually.

It was unused and pointless (use entity.getMeasure() instead).

úprava distribuovaného gridu, okrajové nody již nemají přesahy ve směru kde není soused

Kód obsahuje BUG pro jedořádkové/jednosloupcové distribuce nodů, myslím.