fixed solving homogeneous equation & pep8

removed attribute full_matrices, added tests for `null_space` and
`solve_homogeneous`.
first working version of the visualisation
setup for presentation & fixed requirements.txt
Changed to PyOpenGl and Qt

Pyglet could not be integrated into a gui, so I had to switch
to PyOpenGl.
made steps selective, animation can be turned off
Visualisation is basically working, but still needs small fixes
add various generators for n-dimensional test data
integrate test data into the visualisation
Merge remote-tracking branch 'origin/master' into visual

Conflicts:
	centerpoints/cli.py
	centerpoints/helpers.py
	centerpoints/iterated_radon.py
	centerpoints/iterated_tverberg.py
fixed requirements.txt
Add defaults to evaluation.py -h
Merge branch 'master' into visual
Add new testdata to evaluation