Added Graham Jones' density for root time in birth-death model (when sample proportion is 1.0). Lets test it :-)
Added Graham Jones' density for root time in birth-death model (when sample proportion is 1.0). Lets test it :-)

benb/beast-mcmc,benb/beast-mcmc,benb/beast-mcmc,benb/beast-mcmc,benb/beast-mcmc