ENH: condition number for matrix exponential
MAINT: comment wording
TST: add a condition number test for a matrix that is badly conditioned with respect to expm
TST: expm condition number 1x1 tests
MAINT: use minimize() instead of fmin* and document the norm in which the condition number is computed
DOC: clarify that expm_cond computes the relative condition number as opposed to the absolute condition number
TST: finish converting the slow test from fmin_* to minimize
BUG: sparse: fix some integer wraparounds in sparsetools

Some of the sparsetools routines index into 2D dense arrays.  The
indices into these are not bounded by nnz, and can overflow int32
limits. Take care of this.
ENH Refactor and speed up CSR fancy indexing
FIX correctly handle dense return from csr_matrix.__getitem__
ENH more efficient CSR __setitem__
ENH use np.unique instead of groupby
FIX various logic errors in __setitem__
BUG: sparse: fix int32 wraparounds in BSR matrices

The issue here is that the nnz of BSR is not bounded by the index data
type, which only bounds the number of blocks.  The block size may easily
overflow int32.
BUG: sparse: fix integer overflow in CSR matmat
TST: sparse: add tests probing for int32 overflows
Avoid using np.take(x,x); use mode='clip'
DOC: document how to run slow tests
TST: sparse: add a benchmark for sparse __setitem__ and __getitem__
ENH support CSR/CSC __setitem__ where duplicates interfere

Also use izip instead of zip