tigefa4u projects Trac

VcRefactoring: merge changes from [log:trunk@...:3263]

WorkFlow:

* Renamed `ITicketEnumContributor` to `ITicketAdjunctContributor` for consistency.
* Fixed a bug where the CC field was marked as custom.

Moved `restrict_owner` option to point of use in `trac.ticket.api`.

Fix for #582, with the caveat that indented tables can not have blank lines separating rows.

WorkFlow:

* Ticket similarity detection is now extensible.

WorkFlow:

* Merge log:trunk@...:3258
* Applied fixes from Guillaume Tardif in #3100.

Fix up a small issue that occurs when the ticket cc field is modified

`IOError` doesn't have a `strerror` member, apparently.

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.