fix fillPeaks, which dropped columns and failled if nothing to do

git-svn-id: https://hedgehog.fhcrc.org/bioconductor/trunk/madman/Rpacks/xcms@75621 bc3139a8-67e5-0310-9ffc-ced21a209358
added acknowledgements

git-svn-id: https://hedgehog.fhcrc.org/bioconductor/trunk/madman/Rpacks/xcms@75630 bc3139a8-67e5-0310-9ffc-ced21a209358