Tweaking ImportWXR
Importing Categories as well.
Tweaking import of categories.
Initial Norwegian Bokmål translation for messages in Bolt 1.3.1.
Merge remote-tracking branch 'upstream/master' into norwegian-translation
Merge pull request #768 from hansfn/norwegian-translation

Initial Norwegian Bokmål translation for messages in Bolt 1.3.1.
Tweaking the ImportWXR extension. Way less memory-overhead.