BLD: add numpy requirement to metadata if it can't be imported.

This should help Buildout users.  Closes gh-3379.
Corrected the theilslopes implementation and added a test
Moved implementation to `stats.theilslopes`. Added tests to `stats`.
Added y ties term to the confidence interval calculation.
PEP8 fixes
BLD: add minimum required numpy version to build_requires if numpy not found.
MAINT integrate/odepack: kill dead Fortran code
DEP: deprecate scipy.weave in favor of https://github.com/scipy/weave

And in favor of Cython for new code of course.

Closes gh-3171.
TST: disable slow weave tests for weave.test('full').  Fix TravisCI timeouts.

The slow weave tests will be run if an environment variable RUN_WEAVE_TESTS
is set to True.

Closes gh-3318.
MAINT: minor cleanups to stats.theilslopes.

Add complete references, reST formatting, PEP8, etc.
DOC: add example for stats.theilslopes.
DOC: remove docstring of stats.mstats.theilslopes, use stats version.
Merge pull request #3640 from rgommers/deprecate-weave

Weave: deprecate the module and disable slow tests on TravisCI
DOC: added notes about example for stats.theilslopes. Changed example wording.
Minor changes to docs for stats.theilslopes
DOC: stats: fix wrong option name in power_divergence dosctring example
Changing EPD to Canopy
Merge pull request #3654 from brettrmurphy/patch-1

Changing EPD to Canopy
ENH: initial commit of differential evolution code. A stochastic, population based, global optimizer
ENH: updated scipy/optimize/zeros.py to add differential_evolution