Pull 67 (https://github.com/Automattic/Co-Authors-Plus/pull/67) was incomplete. Contains wp-admin fixes to complete the move to user_nicename.
Updated add_coauthors to use user_nicename.
Tag v3.0.3
Add filters to CoAuthors_Template_Filters for filtering the_author in RSS feeds and hook onto the rss2_item action to add additional dc:creator elements for additional guest authors.
Bump working version number
Merge pull request #92 from cfg/cfg-rss-authors

Add support for guest authors in RSS feeds. Props @cfg
Merge branch 'master' of github.com:Automattic/Co-Authors-Plus
Merge pull request #90 from byt/master

Fix for pull 67: Map author slugs to user_nicename. Props @STRML
Update readme with props for #92
Update readme with props for #90
If it's obvious we're querying for a guest author (e.g. WordPress didn't find a user for this URI), then don't try to include the post_author in the query. On large sites, it means doing a filesort against a lot of rows.
cli: When refreshing author terms, also create new terms for users that don't have them
Bump works up to number
No Co-Authors Plus on attachments for now.

Closes #95
Update readme with mention of MS support
Update screenshots

Closes #97
Readme formatting
Tag 3.0.4
Bump working version number
Update readme with caps explanations

See http://wordpress.org/support/topic/who-can-add-edit-and-assign-co-authors