tigefa4u projects Trac

Switching to a more normalized session table schema for better performance.

Follow-up to r3215: better conversion of Exception objects to unicode string.

There are basically two ways for associating unicode strings to an Exception:
* creating the exception with unicode strings as arguments.
That was the situation handled by r3215, but the unit test for this was
broken.
* implementing a `__str__` method on the exception class, returning an
unicode object. This was not working with r3215 alone. Also added an
unit test for this situation.

Should fix #3088.

SpamFilter: bug fixes, closes #3064.

PermissionPolicy: Merge log:trunk@...:3252

Fix handling of missing extra requirements of entry points in plugin loader.

SpamFilter: added README, and use extra for IP blacklist entry point.

SpamFilter: only test added/modified portions of submitted content.

Apply patch by pacopablo that adds support for using PostgreSQL schemas with Trac. Closes #2711.

Fix timeline messages when wiki-formatted changeset messages are disabled (they were not getting truncated).

Fix default value of the new `wiki_format_messages` option.