ENH: Add check for negative or fractional filter orders (besselap already does it)

Indent imports

Use string for error or else besselap says "not supported for order 3" when it means "not supported for order 3.5"
MAINT: Fix error message for zero, is not positive
DOC: lp2bs mistakenly said it returns a highpass filter
Merge pull request #3091 from endolith/patch-5

DOC: lp2bs mistakenly said it returns a highpass filter
Merge pull request #3083 from tacaswell/bug_empty_label_3082

Bug: should return 0 if no regions found
DOC: More detailed dosctrings for _zpkbilinear, _zpklp2lp, etc.
Merge pull request #2885 from pv/ppform

ENH: interpolate: rewrite ppform evaluation in Cython
BUG: optimize: change default value for catol to match rhoend
DOC: fix typo in signal.ricker docstring.
Merge pull request #3093 from pv/cobyla-catol

BUG: optimize: change default value for catol to match rhoend
BLD: fix Bento build after interpolate.ppoly addition.
MAINT: remove obsolete version checks for < py26.
TST: skip test comparing infs that fails for numpy 1.5.x
DEP: remove deprecated functions in scipy.stats (glm, oneway, cmedian).
MAINT: fix download URL in setup metadata.

This is displayed on PyPi, and was pointing to the 0.11.0 release.
Changing it to not point to a page with direct links to installers is
OK, because pip and easy_install don't know anyway what to do with
those installers.

Has been discussed on mailing list.

[ci skip]
TST: skip test that doesn't work because of buggy object arrays in np 1.5.1
DOC: the type of `exact` parameter
`comb` support combinations with repetition
add tests for comb
add `perm` function