merge from git

git-svn-id: https://hedgehog.fhcrc.org/bioconductor/trunk/madman/Rpacks/openCyto@81940 bc3139a8-67e5-0310-9ffc-ced21a209358
Merge commit '8e32fb764ef1695808cd593487b62583076ff91c' into trunk
fix #66
add more refNode checks in gating_refGate
close #66