first commit in new structure
some more messing with the likelihood directory
messing wih he inference directory now
added some docstrings and the posterior class structure
adding exact gaussian inference
Lots of tidying in the inference section
tidied up gp_base and gp
moved functional part of sparseGP to inference/dtcvar
many dramatic cahnges. at least it import without error.
more massive and destructive changes everywhere
Added the structure to posterior.py  to enable...

to enable computation from the posterior mean and variance, instead of
the woodbury componnents

This iss the first step in being able to use this structre for EP and
the laplace approximation.
more work on the posterior class
adding empyy init file
modified docstrings
merged in params
fixed bug introduced my merge