Merge DomainInformation and SubGrid

Fixes issue #416 

 - move Selection to PMacc
 - merge DomainInformation into SubGrid
 - remove SimulationBox from SubGrid

I tested this with a 128/512/128 4 GPUs LW moving window simulation - images looked good.
~~Note that there might be some documentation still missing.~~
actually, [both](https://github.com/ComputationalRadiationPhysics/picongpu/wiki/PIConGPU-domain-definitions).
the globalDomain.offset += 1 GPU and the localDomain.offset -= 1 GPU.

The sentence in (...) below makes no sense and should read something like
`(currently, only slides in y direction are supported)`