MAINT: split distributions.py into three files
MAINT: remove globals() as suggested by @evr-br
limit search ranges in cdfchn.f
add tests for infinite inputs
deal with nan inputs in cdfchn
BUG: make curve_fit() work with array_like input.  Closes gh-3037.
TST: add tests for numpy version string comparison utility.
ENH: implement lib._version.NumpyVersion which compares numpy version strings.
BUG: incorrect check in NumpyVersion for dev versions.
TST: convert all numpy version checks to use NumpyVersion.
MAINT: take argsreduce and rv_generic back out of the stats namespace
MAINT: move rv_discrete and rv_continuous into the distribution infrastructure module and prune redundant imports
MAINT: remove more redundant imports from the distribution infrastructure module
MAINT: remove unnecessary functions make_dict and reverse_dict
BUG: fix comparison of NumpyVersion's 1.9.0 and 1.10.0.  Closes gh-2998.
Merge pull request #3134 from argriffing/retry-split-distributions

MAINT: split distributions.py into three files
Merge pull request #3166 from rgommers/curvefit-list-input

BUG: make curve_fit() work with array_like input.  Closes gh-3037.
BUG: NumpyVersion object: ``__cmp__`` not supported by python 3.x
Merge pull request #3170 from rgommers/version-compare

Fix numpy version checks
Merge pull request #3153 from richardtsai/issue_3102

BUG: special.chndtr infinite loop (#3102)