issue #300 robustify for non-binary trees
issue #300 robustify for non-binary trees

CompEvol/beast2,Anaphory/beast2,tgvaughan/beast2,Anaphory/beast2,CompEvol/beast2,CompEvol/beast2,tgvaughan/beast2,Anaphory/beast2,CompEvol/beast2,tgvaughan/beast2,tgvaughan/beast2,Anaphory/beast2