Dynamic To-do list per document/project

[Corion]

It would be nice if Padre could show a dynamic to-do list per file or per project, created from all lines that contain

XXX: Needs more cowbell
FIXME:
TO-DO:
Ticket #666

Attached is a prototype that does this.

It needs some enhancements:

* The list does not dynamically refresh
* The list only shows the strings after the marker, but no category
(Categories would be "fixme", "xxx", "ticket")
* The list has no preferences for customizing the regex(es)

Further fun things would be:

* Double-click on a Ticket id jumps to the ticket URL instead of the line in the code, or jumps to both

[Corion]

The Plugin framework to load/operate the todo list

[Corion]

Todo/UI.pm - the meat of the todo list