Correct handling of exclusions by tag when using non-english localization.
Merge branch 'master' of https://github.com/GRiker/calibre

Catalogs: fix exclude tags rules not working in non-English locales when
creating catalogs in EPUB/MOBI formats. Fixes #1228949 [Exclude books for catalogs not functional in German localisation](https://bugs.launchpad.net/calibre/+bug/1228949)