BUG: fix use of np.max in stats.fisher_exact

fixes #3014
DOC: add note that splint assumes the spline function to be zero outside the data interval
Merge pull request #3347 from andreas-h/gh3014

BUG: fix use of np.max in stats.fisher_exact
Merge pull request #3349 from andreas-h/gh1918

DOC: interpolate: add note that splint assumes the spline function to be zero outside...
ENH: Add MLS method