parameters on log scale by default

git-svn-id: http://beast-mcmc.googlecode.com/svn@6556 ca793f91-a31e-0410-b540-2769d408b6a1
Changelog

git-svn-id: http://beast-mcmc.googlecode.com/svn@6557 ca793f91-a31e-0410-b540-2769d408b6a1