1) improved error message when optimization method is wrongly specified in fit function
2) fixed a bug in the summary method for fitted models (in some cases parameters of the prior model were printed in the transition matrix; thanks to Verena Schmittmann for catching this bug)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/depmix@635 edb9625f-4e0d-4859-8d74-9fd3b1da38cb