Adapts Elliptical slice sampler to take a Tree Trait Normal distribution
Functions which used to be exclusive to MatrixParameter were moved to CompoundParameter

git-svn-id: http://beast-mcmc.googlecode.com/svn/trunk@6444 ca793f91-a31e-0410-b540-2769d408b6a1
Create .gitignore
Rebasing against svn repo