tigefa4u projects Trac

TracRevisionLog: improve support for discontinous ranges
- propagate revranges when changing the log options
- the ''Previous revisions'' links to the remaining revisions from the range

Part of #8349.

TracRevisionLog: show ''From r...'' and ''To r...'' tooltips for the Diff radiobuttons.

This is hopefully enough for #4083.

TracRevisionLog: move path_links further down, it's only needed for the html format.

TracRevisionLog: rename second use of `revs` to `revisions`

TracRevisionLog: log TracLinks are now able to deal with range boundaries specified in arbitrary order.

Before, ![1234:1000] would produce an empty range and the displayed revision log would start at ''head'', not very intuitive.

0.11.6dev: Python 2.3 compatibility fix for previous changeset.

TracRevisionLog: when `revs` is specified, strictly respect it, even if it's a range containing a single changeset.

The log: TracLinks had to be adapted accordingly and now they only set `revs` if the TracLinks actually specified a range, otherwise they use `rev`.

TracRevisionLog: Refactor `LogModule.process_request` so that `revranges` is None when no `revs` parameter is given.

TracRevisionLog: in path history mode, the revision row for a delete change had wrong version and changeset links.

TracRevisionLog: in path history mode, we should no keep increased indenting depth after each delete.

Also fixed the indentation of the first test.