Improve localization

[fofajardo]

Most of the locales from AiOS have been removed and placed into the /src/locales/inactive/ directory.

If you want to bring your locale back from the dead or wish to update your locale, feel free to send a PR and make sure that the relevant strings are updated. You can keep track of most string changes through this filter.

In addition to that, you have to:

• Modify this array in about.js to include your language in the about window.
• Include your name here, corresponding with the code of your language.
• Remove the corresponding folder in the /src/locale/inactive/ directory if present.
• Add your language to the list at locales.manifest.

If you've got any questions or need assistance, feel free to ask in this issue!