delete tip dates random walker when deleting MRCAPrior from BEAUti fixes #627
delete tip dates random walker when deleting MRCAPrior from BEAUti fixes #627

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