sigproflik -> z_calculator, which unifies the sample
xsecs/nevents/lumis, input files, weights, and getting event counts
per bin, in addition to doing the PL calculation;

signal_xsec default -> 20 fb;
bigw and syst_frac now options;
nsig/bkg_nm1/total managed by z_calculator class, per sample;
no longer use weighted files, but instead add ourselves in
z_calculator (and remove weight_files function).
samples have colors; samples_by_name map.
total_hist returns a stack for showing the separate background contributions.
Define the z for max'ing in one place.
Clean up options.
debugLevel = -1.
min_nmuons (looser than nsemilep).
Don't let s fall below 5 events in scan.
crab_ownpublish.
dropMetaData; fix output filename from argv.
Add more variables to scan over.
argc min 3; print OK.
Merge branch 'master' of github.com:jordantucker/cmssw-usercode
Print log_fn at end.
Merge branch 'master' into ntuplev13