tigefa4u projects Trac

Also display the documentation for the extension points in the About/plugins page

Some cosmetic enhancements for the About page:
* empty sections in TracIni are skipped (they were not displayed properly anyway)
* component descriptions are wiki-fied

Timeline preferences are now stored in the user session. Closes #855.

Allow extensions to provide custom templates.

We did not always parse trac links correctly, closes #1727

TicketTypes: the ability to change the type of a ticket was lost in the [1831] changes... Restored.

Fix iCalendar view of the roadmap broken by the recent ticket system refactoring in [1831].

Ported [1883] to 0.8-stable.

Quote the cookie path parameter in order to work with paths containing spaces. #1720.

Restart work on the InterTrac branch starting on a recent version (after the [1856] refactoring)