Tmc.nci60

I added nci60.prot.data.R to the branch tmc.NCI60 which shows sparsity of proteomics data
(authors could not get any data for certain proteins in certain cell lines). The
script also returns heatmaps of protein log(intensity,10) values before/after
selecting proteins with log(intensity,10) >=4 in >=5 cell lines. It also plots the
average expression for proteins showing the same frequency of N/A values overall
cell lines.