Got Specs and HistogramManager working

generate_stats.py now successfully runs again.

I'm still missing the StatsManager step of actually calculating
statistics on all these histograms, however.  The code has been
translated but it's not yet been tested.
Plotted one of the 726 histograms
Changed histogram to bar graph

Also a couple of other small changes
Small changes to histogram plotting

Also fixed a typo
working on HistogramManager.merge
working on HistogramManager.merge
Got HistogramManager.merge working

Hopefully the fact that it only generates 673 histograms instead of 700+
is because I've turned the eccentricity calculation off via
user_config.py.
Improved plotting
Working on stats_manager
Merge remote-tracking branch 'remotes/upstream/master'

Conflicts:
	movement_validation/features/worm_features.py