improve translation syncing

This should improve the syncing with transifex, but there are still bugs with how transifex handles xliff tags.  So `tx pull --all --force` will get the translations, then the various `./fix-*` scripts need to be run to remove some of the known issues.  Even with these fixes, `tx push` will not do the right thing yet, so it should not be used, except for the source file, i.e. `tx push --source`