tigefa4u projects Trac

Make the wrapper for PySqlite cursor a bit more robust, and position some disabled ''print'' debug statements. Related to #4128.

Improve the ''Index by Title'' page.

Now, the !TitleIndex macro supports an additional ''group'' format, e.g.
{{{
[[TitleIndex(format=group)]]
}}}
which structures the output according to the common prefixes found in the Wiki page names.

Closes #1461.

Another small template fix related to [Genshi 421]

Propagate `req` as needed from `wiki_to_link` down to `Formatter`

Finish the TracTimeline refactoring:
- the RSS templates are now using `absurls=True` where relevant
- removed the `to_abs_href` helper function; instead, added a new `abs_href(req)` to the !TimelineEvent class. This makes it easier to assign absolute hrefs to timeline events, if needed.

Moved the wiki_to_* calls in the templates for the TracBrowser and TracRevisionLog views

* Remove extra dash from the title of the start page
* Make the browser option `hidden_properties` a `ListOption`

Simplify the Genshi template for viewing reports

Move wiki_to_x calls to the templates for the TracReport module. Also fix the report view for [Genshi 421].

The Changeset module implements the new ITimelineEventProvider interface. Also added the necessary wiki_to_x calls in the templates. Fixes #4023.