translation cleanup

[danbjoseph]

storing all the translation files in the repo doesn't seem to be adding much value, and ends up with LOTS of changed files every time there's a change and we want to update all the languages. this PR takes those files out of the repo, and pulls the language strings down from Transifex during the build process. currently, in order to push changes that have occurred up to Transifex for translation, we still need to run:

make updatepot
make updatelangpo
make pushlang

but that could be changed to occur during the build process as well.

[pierotofy]

Thanks @danbjoseph 👍 I think this might have some issues with the build command make pulllang, for example on a brand new environment I get:

make pulllang
tx pull --language "sw,ar,es,fr,te,fil,id"

Did you know that you can create an apitoken under your transifex user's settings?
(Read more at https://docs.transifex.com/api/introduction#authentication)
So, do you have an api token? [y/N]:

So the automated build would hang here.

[danbjoseph]

ah, you're right, i completely forgot about that piece. i'll look into if it's possible to get around that securely.