More backend changes.
Merge remote-tracking branch 'Hello71/morewin' into DF2014
fix role preferences, remove bad role prefs

- removes generic metal/stone/gems/alcohol preferences from all roles,
since every dwarf has one of these preferences
- adjusts the role calculation to give better preference ratings
merge fixes, role pref cleanup and fixes

- changed rolestats to better show what method is being used
- added the capability to override the transformation method in
rolestats (currently only used for preferences)
- fixed leftover ATTRIBUTES_TYPE enum changes from #167