tigefa4u projects Trac

Title for generalized diff is a bit more compact: ''Changes from `_old_path_` at r`xy` to `_new_path_` at r`yz`''

Only show the ''View changes'' button if there are more than 10 entries shown. This change concerns both the revision log and the wiki history.

TracDiff cleanup: the ''View changes'' button on TracRevisionLog now directly sends the diff request to the TracChangeset module (no redirection involved anymore)

TracDiff: the title for displaying a set of changes on a given path is now more compact, and links to the corresponding TracLogRevision view

The TracDiff branch is not needed anymore.

TracDiff merged in trunk, as a new feature for Trac [milestone:0.10]

* debian/patches/10_securityfixes.diff (Closes: #348791):
Fix CVE-2005-4065 and CVE-2005-4644 vulnerabilities.

Tag debian security update.

Merge changes did by Martin in his last security update.

Refactoring of TracCrossReferences: create `trac.xref` module

The cross-referencing facility has been separated from the TracObject.

In the `trac.xref` module, there's now a separate file for the Web UI
and the macros (that's fine, as there will be more macros in the future).

Finally, the API for the xref has been simplified and the documentation
has been updated.