classroom 6.x-1.0-beta6

This release contains a lot of bug fixes and some new features, so upgrading is highly recommended.

Here is a summary of the more important changes:

• Support for topics: assignments and resources can be organized into topics.
• Fixed an issue in the assignments page which caused assignments to be shown
  multiple times.
• Bug #596130: Fixed SQL error when using table prefixes.
• Bug #613344: fix an issue with nodes when using table prefixes.
• Feature #622314 by laserlight: The 'login' link is shown instead of 'sign up' when user is anonymous.
• Added a course's description page.
• Added a course's topics block.
• Added 'updated' and 'new' marks to assignments.
• More fixes in dates handling.
• Other minor bugfixes.
• Other minor UI improvements.

Feedback is welcome.

Enjoy!