update to phenotypePhasePlane

Speed improvements: computes 40x40 plane in under 3 seconds using cglpk
on my machine (on a single process).

Allows theming through brewer2mpl (if installed). Nicer default theme.

Azimuth and elevation automatically set on figure creation to more
sensible defaults.
graduate phenotypePhasePlane into flux_analysis

from the oven
relative import for phenotypePhasePlane.py