Removed superfluous grid run by returning map from subgrid list

This kind of replacement should be possible in a couple of different places too.
Whitespace cleanup and docu
Added methods returning subgrid for a coarse codim 0 entity
Added local solution manager
Whitespace changes
Added local solution manager (this time with file content and build system)
Add function to specifier returning whether coarse grid is made up only by simplices

This is needed to decide how many local problems
there are.
Cleanup in local solution manager
Some variable renaming and code reordering
[msfem] added method to compute all local solutions "at once"
In non-lod case, all local problems are now solved in one method
Added method assembling rhs for all local problems in one grid run
Coarse quantities are assembled correctly on non-simplex grids
adapted identify_fine_scale_part for non-simplex grids
Added two typedefs to MsFEMTraits to distinguish between coarse and fine entities