clean up init

set most variables on Zotero.config directly instead of transferring from
zoteroData
fix State.getSelectedItemKeys

needs some preprocessing to deal with conflicts between multiple checkboxes
for the same item introduced with responsive layout (and also possible with
alternative layouts). getSelectedItemKeys will now just return a set of
unique itemKeys.
(also fix missed edit from last commit)
make colored tags bold+colored text like client
fix note editing

- fix edit note template
- clean up ckeditors before destroying underlying dom elements