remove fixed FIXME note from Settings screen code
copy translateable strings from Settings view into ui/Languages.lua
strip all unused strings from LangStrings.inc.h
add a python script to clean up language data files

This strips out translations for tokens that aren't declared in
LangStrings.inc.h, and cleans up whitespace. Entries are left in the
order that they appear in the translation file, and blank lines and
comments are left as they are apart from stripping excess whitespace.
strip unused tokens from the translation files and clean up whitespace

(changes applied automatically by clean_lang_data.py)
copy available translations for the settings screen from lang files

I have only included languages for which there is already a section in
data/ui/Languages.lua; it doesn't seem worth adding extra language sections
for other languages, since they clearly have not been updated at all
recently.
change label for anti-aliasing setting to "Multisampling"