Initial implementation of the voro++ wrapper.
A round of autopep8.
New version of the voronoi helper class.

Cleaned up the old, unused bits, added the possibility of returning the vertices
and added a plotting method based on mayavi.
A round of autopep8.
Add initial support for the walls.
A couple of changes on the fortran side to account for the new convention
regarding domain walls. Still not working properly.
Fix a problem in the indexing of neighbours on the voro++ side.
voro++ does not work well if a site is exactly on a domain wall. Make a check in the init code
more strict to check for this, and rework the logic in voronoi_grid.py to add a bit of padding
to the auto-detected domain walls.
A round of cleanup and documentation for the Voronoi code, plus the first test
in Hyperion.
Add some testing code for the voronoi helpers.
Merge pull request #4 from bluescarni/voronoi_take_4

Voronoi take 4