Changes in version 2.10.5                        

BUG FIXES

    o   corHMMDredge no longer proposes structurally invalid models
	during simulated annealing. The "drop" move could remove the
	last remaining free rate, producing an all-NA index matrix;
	this gave a no non-missing arguments to max warning and an
	invalid 'times' argument error, which was caught internally and
	so did not affect the returned models. Proposals are now
	checked at every rate category: a model must retain at least
	one free parameter and no state may be isolated (NA in both its
	row and its column). Irreversible models, in which a state has
	rates in only one direction, remain in the search space.
	corHMMDredgeBase now also rejects a degenerate rate.mat with an
	informative error.

USER-VISIBLE CHANGES

    o   Because invalid proposals are no longer generated, the random
	number stream during a dredge has changed. Runs using seed will
	not reproduce the trajectories of earlier versions. Dredges
	with hidden rate categories may also skip degenerate models
	they previously fit and accepted.

                       Changes in version 2.7.1.4                       

USER-VISIBLE CHANGES

    o   Equate/DropStateMatPars will take empty lists (and return the
	original matrix)