[dev] Kronolith patch - color + category

[Chuck Hagenbuch]

Quoting Joel Vandal <jvandal@subi.to>:

>  - A new class for category management for each application (like :
> lib/CategoryUser.php)

I'm thinking of renaming the current Category class to something like
Hierarchy - or Tree - that better describes what it does.

>  - Create sub-category (parent/child)

... but if we're going to do this, maybe we should just have a
Category_prefs driver for simple stuff?

>  - Automaticaly change the color of the category when choose a new color
> (but only save when user click on save button)

Cool.

> A lot of Horde application (Kronolith, Mnemo, Nag, Trean(?)) have
> category support.

Yeah, it'd be great to get the code in one place.

-chuck

--
Charles Hagenbuch, <chuck@horde.org>
"After a few minutes the most aromatic and nice smelling Italian coffee 
 will come out of the exhaustpipe." - Our stove-top espresso pot