more tweaks for #36, preference tooltips

- updated the preferences section in the unit tooltip to categorize and
give better descriptions so it's easier to pick out materials or food.
- updated the script filtering to properly look in specified categories.
eg gems could match both items 'large gems' or shapes 'gems'
- adding a filter from the preference dock gives a better description of
what the filter contains
- creatures are added to multiple lists in the role preference section
(eg. rats are trainable and hateable)