more msnbase.r and testing if features left after filtering in readIspyData

git-svn-id: https://hedgehog.fhcrc.org/bioconductor/trunk/madman/Rpacks/MSnbase@72375 bc3139a8-67e5-0310-9ffc-ced21a209358
Merge branch 'local-hedgehog'
fixed conflict