Fix part 2 of categorization's broken css

Summary:
This makes the categorization editor's css
strictly more specific than the categorization
widget's css, so that the editor always uses
the editor's css, regardless of which was loaded
first.

Test Plan:
 * substate
 * Make a categorization in devappserver
 * ensure that the items and categories fit next to each other

Auditors: brianmerlob