ENH: interpolate/polyint: allow polyint evaluation on arbitrary shape arrays
ENH: interpolate/polyint: make the polynomial interpolators able to deal with arbitrary-shape y data arrays
TST: interpolate/polyint: add tests for y-shape
BUG: interpolate/polyint: deal with complex-valued arrays
ENH: interpolate/polyint: refactor interpolation axis support in polyint

Support dealing with the interpolation axis using the same mechanism in
all of the interpolators.
MAINT: interpolate/polyint: rename Pchip -> PchipInterpolator
BUG: interpolate/polyint: fix divisions by zero in pchip
STY: interpolate/polyint: make the code a bit more readable
ENH: interpolate/polyint: make the derivative axis be always first in the derivatives() methods
DOC: interpolate: update the polyint documentation to match the implementation vs. axis and shapes
STY: interpolate/polyint: rename InterpolatorBase -> _Interpolator1D
Merge pull request #221 from pv/ticket/1021

ENH: interpolate: allow polyint evaluation on arbitrary shape arrays

Conflicts:
	scipy/interpolate/polyint.py
	scipy/interpolate/tests/test_polyint.py
Merge branch 'merge-gh-221' into merge-pull-221
BUG: fix range/xrange issues due to removal of 2to3.