WIP: Updates to steady state module

Added ARPACK eigensolver, updated power method to use RCM, start from
maximally mixed state, and not recalculate LU factors everytime solver
is called.
Remove the README.txt for CPC from the repository: only needed for CPC submission, and no need to keep it here
updated changelog in RELEASE.txt
updated url in debian control file
Merge pull request #186 from jrjohansson/3.0-release-updates

minor pre-3.0 release updates
Moved _version2int to utilities module

Also removed _version2tuple
Updated cython files with parameters.pxi file
Added maximally mixed state
made reordering function names more explicit
updated sparse tests with new names
updated steady state solvers and testing functions

- added weighted_bipartite_matching to reordering

- added new eigen solver

-much updated power solver

-combined iterative methods into single function

- dropped support for bicg solver as the new scipy.sparse.linalg docs
suggest that this method works for Hermitian, positive definite
problems only.
Fix for missing BLAS under Windows Anaconda
revert to old fortran setup
Fix for windows BLAS
minor code fixes in qip.models.cqed
make sure that T is positive
fixed label error
minor code and docstring cleanup
minor code and docstring cleanup
doctring updates