fix mistake in i18n
i18n some words in forum
Fix issue #2012
Try to workaround an assertion
Merge pull request #3 from smartdec/feature/i18n_in_forum

Dirty fix, but still merged:( #1755
fix #1761 and #1648
i18n title in some placeholder
Fix missed message for issue #1777
Problem categories i18n
Problem creation l10n
Fix a typo
i18n word
#2028
fix mistake in last commit
Update l10n
Merge remote-tracking branch 'origin/select/release' into feature/xmodule-i18n

Conflicts:
	common/lib/xmodule/xmodule/capa_module.py
	common/lib/xmodule/xmodule/master_class_module.py
	common/lib/xmodule/xmodule/peer_grading_module.py
	common/lib/xmodule/xmodule/templates/problem/drag_and_drop.yaml
	conf/locale/ru/LC_MESSAGES/django-partial.po
	conf/locale/ru/LC_MESSAGES/djangojs.po
	conf/locale/ru/LC_MESSAGES/mako.po
fixes and l10n