Merge pull request #1 from chapmanb/master

Fixes to support runs on small test samples
plots: pulled out colors into definitions at the top of the module
Added citation info for the bioRxiv preprint
segment: Add option to save R dataframe; handle more versions of CBS maybe?
segment: Handle CBS dataframe with field named either "sample" or "sampleName"
doc: updated and fixed command-line examples (thanks Melissa!)
Merge branch 'master' of github.com:etal/cnvkit
Provide ability to pass an R libpath when supporting libraries are not located in standard R paths