Fix license on DroidSansFallback.ttf.

According to

    https://github.com/android/platform_frameworks_base/tree/master/data/fonts ,

the Droid fonts are under the Apache license.
Remove +x bit from Chinese translation.
Remove TODOs from simpified chinese translation.
Remove text from Chinese translation, per:

https://github.com/renpy/renpy/pull/365#issuecomment-44358481
Rename Chinese_Simplified -> simplified_chinese.

This makes the naming similar to the other languages we support.