Update condor run configuration.
Bring plotting standards up to date.  Colorscheme is still missing.
Reorder cuts to match order in Nidra.
Implement proper exceptions and be more verbose.
Implement process splitting.
Fix selection by isolation.
Be verbose by default (when running on the cluster).
Move the filling of histograms to C++ code.

This helps our memory consumption (down to ~500 MB from >6 GB), while
keeping complexity at bay through new helpers: Picker (combination
selection) and Splitter (sample splitting).
Do some clean-up.