Now returns natual log of dT

dT is now defined at the natural log of 1 + the sum of the Euclidean
distances between points. This log transform avoids the problem where
scaling super-skinny triangles results in a triangle that is crazy long
and therefore extremely distant from another more normal triangle
(which in turn skews the Pearson correlation).
Triangles imported as Numy arrays

Triangles are now loaded in as Numpy arrays so that they are properly
compatible with the geometry.py module.