Localization

[micahflee]

We should start separating out all of the text in the application to into a separate strings file so we can begin to build the infrastructure for translating securedrop into several languages.

Then I think we should make a Transifex account and upload our English strings file and start recruiting translators.

After we have more than one language, we should build a drop-down menu in the theme (like maybe the top-right corner) to switch between languages. It could maybe store your preferred language in a session cookie.

Having securedrop localized in several languages is one great step, but another (and harder I think) step is getting all of the related documentation translated into other languages.

Since at the moment most of the securedrop user-base seems to be in the United States, Spanish would probably be a good second language to aim for. Though I actually doubt we'll have any problems getting all of the strings for securedrop translated into several different languages pretty quickly once we have it in Transifex.

[runasand]

Duplicate of #127.