tigefa4u projects Trac

Add back 'update' key to fix changing diff options in wiki. Closes #1643.

Fix changing the diff options in the wiki diff view. Closes #1611.

TracDiff interface enhancements:
* less intrusive ''Diff'' panel in the Browser and the Log view
* the panel is not shown when browsing the ''root''
* more consistent specifications of path/revs
(don't try to use the created_path/created_rev information)
* Improved the display of the title for the Diff module
* added a ''Reverse Diff'' link in the Diff module,
to invert the '''from''' and '''to''' parameters
* while showing the diffs entries, show the created revision information
for the old and new files, not the global ''old'' and ''new'' revisions.
This is especially useful while diffing between branches,
so that one can see which side is the most recent on a file per file basis.

Better error message when requesting a non-existent changeset. Closes #1630

Offering a ''Plain Text'' download should not be solely based on whether the file has a MIME type that is a sub-type of {{{text/}}}, because that excludes text files with MIME types such as {{{application/xml}}} or {{{image/svg+xml}}}. Use the {{{trac.mimeview.is_binary()}}} function instead.

Display line numbers for files in the repository. Closes #520.

Added the possibility to download text files as plain text (''text/plain'' mime-type) in addition to their ''original'' format. Thanks to xris for the idea (#1637).

Fix wrong URL to custom query from report module.

First iteration of TracDiff. Corresponds to [http://projects.edgewall.com/trac/attachment/ticket/199/diff_module_beta1.diff diff_module_beta1.diff]

TracDiff: created a branch to work on #199