restructure qutip.sparse so that it is independent of Qobj. All methods should use a constistent naming sp_xxx and should only operate on sparse matrices
no global import of qutip.sparse
no global import of qutip.sparse
change qobj/entropy/metrics to use functions in qutip.sparse by passing qobj data instead of qobj
use sp_permute/sp_bandwidth instead of sparse_xxx. Only import the required functions from qutip.operator
rename test_Sparse to test_sparse
rename test_Sparse to test_sparse
fixed tests for renamed functions and isolation of qutip.sparse from qutip.qobj
more fixes in sparse unit tests for changes made in qutip.sparse
pep8 fixes in test_sparse.py
pep8 fixes in test_graph.py
pep8 fixes in test_sp_eigs.py
reorganized implementation of sp_eigs: split into functions for sparse and dense eig functions
Merge pull request #158 from jrjohansson/refactor-sparse-module

Refactor sparse module