focusing on groups of type 'team'.
* Simplifies managing the Abstract for uploaded group materials.
Displays the abstract on the groups materials page
* Provides SessionPresentation: a binding between
Document and Session objects, that tracks doc version.
* Adds helpers for finding upcoming sessions, and the
most recent SessionPresentations whose sessions have passed
* Generalizes the snippet concept (as a templatetage) used
in the history tab for use on other pages
* Adds a variant of the snippet that can be styled as an edit link
* Provides several ways to address sessions, using sequence,
dates, group acronyms, and day of week
* Adds a 'Materials Manager' Role
Commit ready for merge.
- Legacy-Id: 8711
b4448a8faa