Extract i18n strings from *.underscore files using django-babel-underscore
Extract i18n strings from *.underscore files using django-babel-underscore

Change strings from mako.po into underscore.po, which is finally merged into djangojs.po.
Merge pull request #3971 from louyihua/django-babel-underscore

Django babel underscore
extract from underscore files under cms, lms, and common

to avoid extracting from test_root and such
Don't search for underscore files under lms
Babel underscore extraction update according to @nedbat

1. Add underscore.po into the merge section in config.yaml
2. Using one babel command template to construct two babel commands
Merge pull request #3988 from louyihua/django-babel-underscore

Babel underscore extraction update according to @nedbat
Merge pull request #3965 from edx/db/django-babel-underscore

Extract i18n strings from *.underscore files using django-babel-underscore