Multitype OU Processes with varying alpha and sigma

Been meaning to sit down and work this one out for a while; somehow travel and conferences helped out with that – now I only have to transcribe some dozen messy hotel notepad sheets to get the calculations into this lab notebook. Meanwhile, 15 hours on a train from Portland was just the right amount of time to code up the approach, which is now implemented at the C level for the Anoles dataset; code in the wrightscape project on github.

- current algorithm will replace the existing codebase for the wrightscape project. Currently the makefile, p_multimin.c, and piecewise_regimes.c (the main file) contain the standalone version of the new method. Will soon remove older scripts from the active version and break up piecewise_regimes.c into multiple files as appropriate.