[hu] recover from Mercurial (seamonkey)
[sl] pull from Pootle (thunderbird)
[sl] pull from Pootle (thunderbird)
[sl] pull from Pootle (thunderbird)
Config: drop tarball building
Tools: always build langpacks

Output into POOTLE_EXPORT directory and keep the log. Recover files that we
need for the langpack build.