Rename paper types

Currently paper types have numbers prepended (e.g. "1. Journal"), so that they're ordered so that the weightiest papers appear first. If you're missing a paper type (e.g. you have no journal papers), then you'll see a gap in the numbering. To fix this, the numbers should be removed when displayed:
http://bibbase.userecho.com/topics/68-change-type-display-names/