Add support for non-english locales

[gravestench]

related to #863

Currently, using a non-english locale will cause a crash.

We need to use the locale from the mpq to load specific string tables and fonts. See #863 for where the local is stored. exactly which sting tables and fonts get loaded needs to be determined.

[M.Sz.]

I think, it can be closed now.

[gravestench]

resolved by #927, #929, #931