Merge pull request #170 from arokem/westin_stats

Westin stats
ENH: Non-linear least squares tensor fitting.
ENH: First-pass implementation of RESTORE.
RF + TST: RESTORE.
RF: Simplified the tensor decomposition.
DOC: Small comment change.
TST: Make the tests more runnable.
RF: Silence some runtime warnings.
RF: Replace fmin with leastsq.
TST: update the test to the new API.