beast 1.7.5: New formula

BEAST is a cross-platform program for Bayesian MCMC analysis of
molecular sequences. It is entirely orientated towards rooted,
time-measured phylogenies inferred using strict or relaxed molecular
clock models. It can be used as a method of reconstructing phylogenies
but is also a framework for testing evolutionary hypotheses without
conditioning on a single tree topology. BEAST uses MCMC to average
over tree space, so that each tree is weighted proportional to its
posterior probability. We include a simple to use user-interface
program for setting up standard analyses and a suit of programs for
analysing the results.

Closes #175
beast 1.8

Closes #503