tigefa4u projects Trac

* Use wiki model class to implement the `wiki remove` command in [wiki:TracAdmin trac-admin].
* Auto-complete wiki page names on `wiki remove`

Treat some file format as binary, even if the binary detection heuristic fails.

Those files can be considered ''semi'' binary, as they are basically non-human readable
(PDF, PostScript, RTF), but the link to the ''Plain Text'' alternative format is nevertheless
made available for those who really want to look at it.

Follow-up to [2101] which removed the credits information (?). Those changes where needed in order to fix the unit tests.

Edgewall's Trac can now also render its own Wiki formatting for files stored in the repository. Let's make the set of default wiki pages benefit from that feature. That way, eventual formatting errors can be spotted directly from the main repository.

Added a slightly more user-friendly concurrent wiki editing detection. This also closes #1739.

As Edgewall's Trac now support rendering reStructuredText files in the TracBrowser, I noticed I forgot to set the property to on the RELEASE file.

Make the `search:` link syntax consistent with the `query:` one.

That is, one can construct complex search queries by starting the query
argument with a `?` sign, followed by the search query parameters
as they would appear in the URL.

E.g. `search:?q=link+syntax&wiki=on` will prepare a link for
searching about ''link syntax'' in the wiki pages only.

Fixed search: link syntax. Fixes #1937.

Make sure we generate a valid rpm spec files. Closes #1141 (again).

TracDiff: 2 small fixes
* ''Last Changes'' link in the Browser was using the current rev,
not the ''created rev'' as it should have
* fixed diff arguments for the alternate format links in the Diff view