Rename minimality_test_general.sage to discontinuous_case.sage
generate_*_vertices: Move continuous code to its own file and dispatch to continuous and discontinuous cases.
Update minimality_test functions using general (discontinuous) code.
Update plot_2d_diagram using general (discontinuous) code.
Update check_perturbation using general (discontinuous) code.
Update finite_dimensional_extremality_test using discontinuous code
Move generate_maximal_additive_faces (continuous case) to continuous_case.sage.  Dispatch to continuous and discontinuous case.
Move continuous perturbation code to its own file. Update from discontinuous code and dispatch.
Remove code duplication regarding covered intervals in discontinuous case
Update extremality_test with discontinuous code
plot_covered_intervals: Use is_continuous instead of is_continuous_defined
Add docstrings
Add docstrings
Update file list.