:bug: Wrong binding for TETRAHEDRAL topology
Merge pull request #144 from bempp/rsdt/cython_grid

Rsdt/cython grid
:bug: in tests from bempp->libbempp target change

Introduced in c125db1. Did not correct test projects then.
Remove unnecessary file
More explicit docstring for range_accuracy_options
Cython 0.19 does not allow dosctrings for variables in pxd files
Merge pull request #153 from bempp/rsdt/cython_context

Rsdt/cython context
Merge pull request #155 from bempp/rsdt/cython_spaces

Rsdt/cython spaces
Grid hierarchy is Cython wrapped. Some methods still need to be implemented.
Merged operator branch and fixed pointer issues in entity and geometry class