new bspline_vector_space.py. class for bspline
added test bspline file
base version of the constructor and test running properly
Added compute_n_dofs and compute_mults
Added tests for compute_n_dofs and compute_mults
base constructor and test working
Added cell_span method with test
Fix cell_span in a more pythonic way ;)
Added basis, plot_basis_functions, map_basis_cell, find_span methods and a shared library in utilities.