tigefa4u projects Trac

Directory expansion: restore latest expanded folder, based on location anchor.

Implements #7074.

Directory expansion: update the window.location anchor with the latest expanded folder path.

TracBrowser: add 'r' keybinding for reloading a folder

CTRL+R should still be able to do a full reload.

TracBrowser: add two more key bindings:
- 'a' for going to the annotate page
- 'l' for going to the (change) log

Also fix keyboard navigation to the upper level.

Directory expansion: allow error rows to be reloaded.

Add `$.template` Javascript helper function, for simple string expansion of keywords.

Clarify HTML snippet for the creation of the "Loading ..." row by using less jQuery API

Doesn't work with old versions of Opera (syntax error for `/\$.../`).

MultiRepos: rework r7964 - keep possibility to notify using the repository dir, but also support having multiple scoped repository defined on that base repository.

A bit like what `get_base` does, but focused on the simplicity of re-using the REPOS info available in the hook.

MultiRepos: if one wants to keep the auto-enabling of the trac.versioncontrol components, the `repository_dir` has at least to be ''present'' in the `[trac]` section (it can be empty, as per r7970).

MultiRepos: as changesets can be present in multiple repositories, the timeline event shows the list of repositories where the corresponding changeset can be found.