tigefa4u projects Trac

TracGuide: merge recent changes made on t.e.o

TracGuide: merge recent edits made on t.e.o

Follow-up to r6298: actually ''add'' that TracFineGrainedPermissions file...

TracGuide:
- integrated the new TracFineGrainedPermissions page (#3636)
- selectively integrated other changes from the t.e.o wiki

Fix use of uninitialized var in `get_timeline_link`

Add more debug output by default for the AuthzPolicy sample plugin.

(contributed by Stephen Moretti)

Add revision information for each single file sample plugin, so that there's some basic tracability when inspecting the plugin source files.

Add a fallback for the "trac:" InterTrac prefix, if not already defined in the `[intertrac]` section in TracIni.

This is useful for referring to additional online resources from the built-in documentation pages, like additional Wiki pages or even tickets.

(Note: regarding hard-coding t.e.o URL vs. taking the home-page info from the package, I preferred the simpler approach which I think is OK given that trac.edgewall.org is already mentioned in every source header)

Follow-up to r6292: oops, that change wasn't intended to be part of that changeset

Fix a few remaining references to old http://projects.edgewall.com/trac (p.e.c for old timers) and replaceit by http://trac.edgewall.org (t.e.o)