Download normalized NCI60 133plus2 data and write expression matrix
and SummarizedExperiment.  May be a somewhat generalizable procedure, but
there were several quirks in the downloaded data.
ovc_ehub.Rmd creates various options for copy number and expression for an eHub.  Additional copy number files from GISTIC2.0 output. Added key2GRanges() function, using lots of code from exs2se().
Merge pull request #20 from lwaldron/master

Progress towards an eHub for ovc