Mesh simplifications

[wdeconinck]

Removed functions:

• Entities::get_coordinates()
• Entities::put_coordinates()
• Entities::allocate_coordinates()
• Entities::node_connectivity
• Entities::get_nodes(elem_idx)

The correct way to access is now respectively:

entities.geometry_space().get_coordinates(...);
entities.geometry_space().put_coordinates(...);
entities.geometry_space().allocate_coordinates(...);
entities.geometry_space().connectivity();
entities.geometry_space().connectivity()[elem_idx];

It is more straightforward where it is accessed from, and is of course the same for all other Spaces as well.

[tlmquintino]

Well done.