Properly fix previous calls to matplotlib points_inside_poly.

matplotlib deprecated points_inside_poly in 1.3. A patch was previously submitted to fix this (https://github.com/OpenElectrophy/OpenElectrophy/commit/bb5189f55114ecbcb64f104c2e3ed0251e64383a). However it wasn't a proper fix for the following reasons:

* It replaced the points_inside_poly with a call Path.contains_points, but it didn't replace all the calls to points_inside_poly.
* Second, from what I could tell, matplotlib 1.1 does not have the Path.contains_points function yet, in the home page OE specifies that matplotlib 1.1 satisfies the requirements.

This patch (based on https://github.com/newville/wxmplot/pull/14) replaces all calls to points_inside_poly, and selectively calls either points_inside_poly, or Path.contains_points depending on the version of matplotlib installed.