tigefa4u projects Trac

Pass req through to post request filter method.

Make the output of [wiki:TracAdmin trac-admin] more readable on small terminals. Fixes #2496.

Slightly clarify [wiki:TracStandalone tracd] command line argument, so that the project directory doesn't get confused with the project name, as suggested in #3218

Don't truncate headings, which was done by mistake in r3353. Fixes #3225.

''Reply'' to ticket changes feature added.

* Added ''permalinks'' to ticket changes, using the same look and feel
as those for Wiki section headings.
Note that those permalinks are now also visible when using IExplorer.
* Added inlined ''Reply'' button for each permanent change;
when ''replying'' to a change, the comment associated to the
replied-to change is simply copied and quoted in the comment
textarea. A subsequent change is then recorded to have been
''in reply to'' the former change, enabling some kind of threading
of the comments.
* A permanent change correspond to a modification of the ticket;
ticket changes due to attachments are qualified as non-permanent changes,
as in the current way things work, this kind of change can come and go
(e.g. when the attachment is replaced or deleted)
* there's a new `comment:` link resolver:
- referring to change `n` in the same ticket: `comment:n`
- referring to change `m` in ticket `xyz`: `comment🎫xyz:`
(similar to the `attachment:` link resolver)

Fix for request post processor missing argument.

The changesets belonging to a given time period are now retrieved directly from the cache. This is not only faster, but that implementation should be valid for most VersioningSystemBackend. Thanks djc for the patch.

Minor tweak to last commit.

Add support for VIM's `syntax=<n>` directive when detecting MIME type.

Fixed ticket conversion tests, better documentation for `convert_content()`
method and no longer silently drop and log exceptions inside converters.