Regenerate POT file

[mindctrl]

Once #25 is merged and right before we tag 1.3.7, we need to regenerate the pot file so it includes all the strings.

[nathanrice]

I'm not sure what tool AB uses for POT generation, but I know that the WP.org tool doesn't scan JS files for translatable strings, and neither does the grunt-wp-i18n task. (AFAIK)

This Babel plugin does, though.

[mikemcalister]

I thought CGB was doing POT but I guess not. There are some more clues here and here.

[mikemcalister]

Ultimately used wp i18n make-pot in wp-cli to regenerate the strings in 1.3.7. More on that here.