Add part 4 of capture-recapture data.
Small modification to prior.
Merge branch 'staging' of github.com:jashapiro/jashapiro.github.com into staging

Conflicts:
	courses/biolB215s13/_capture_recapture4.Rmd
	courses/biolB215s13/capture_recapture4.md
	courses/biolB215s13/plots/capture_recapture4-priorplot.png
capture-recapture example file