Use $DEVEL_DIRECTORY instead of $BUILDHOME.

I guess the former was automatically generated by Paladin (although it works, I've seen some other programs use the above).
Use short names for libs.

E.g. libbe -- be, libmedia -- media, etc.
Add Spanish language file.

For future reference (and possible use in the game).
Delete old Spanish language file stub.
Merge pull request #2 from louisdem/patch-2

More patches.