Problem

I don't see a reason why it shouldn't be configurable and think it would be a great enhancement to have caps on errorbar-plots enabled by default (in context of stylesheets) and not having to set them each time I call plt.errorbar(...).

Proposed solution

I'd like to see errorbar.capthick and errorbar.elinewidth to be configurable via stylesheets.

# errorbar props
errorbar.capsize:    ...  # already existing
errorbar.capthick:   ...
errorbar.elinewidth: ...