i18n - extracting new, pulling from tx

fixes #8874 - rework POT/PO updates for gettext 3's edit.po

3.1.13 adds an intermediate .edit.po file alongside each .po, which is meant
to be kept outside of SCM and updated by users, whereupon it's merged back into
the .po on the next rake gettext:find execution....

refs #11216 - remove update-rails from locale update steps

fixes #8019 - convert po to JSON before refreshing pot/po files

fixes #4178 - updating i18n extracting rake task and makefile

fixing transifex domain in .tx/config and scripts

fixes #2536 - loading locale .mo files in production mode

- initializer script fixed to look for .mo files
- Makefile updated to place *.mo into /locale//LC_MESSAGES
(rake gettext:pack places them there as well)
- *.mo files added to foreman.spec

fixing transifex parse error

Feature #2368 - i18n extracting strings

Feature #2368 - renaming i18n domain to 'foreman.pot'

Feature #2368 - i18n integrating Transifex