[Laszlo-user] "Enhanced" grid

[Yang]

After studying the grid family of classes, I performed some surgery on
it to create a really hacked up grid that supports my own needs -
specifically:

- node-based columns
- cell-specific bgcolors
- dynamic changes to columns
- oncellfocus(who) events

It's a bit scary and has some quirks in the focus model. It's available here:

https://assorted.svn.sourceforge.net/svnroot/assorted/lz-xgrid/trunk/src

This helped me learn a lot about Laszlo since I just started using
Laszlo a few days ago. Grids are usually the most complicated
components in any GUI framework, and here was no exception. I always
thought that a very good test of a declarative reactive GUI
programming system is whether you can implement a fully featured grid
using the system's declarative constraints/replication/data-binding,
as opposed to the current version of the grid, which is far from that.

I'm not sure if it's possible to do this in Laszlo/if Laszlo would
pass this test. I think that would be an interesting, fun, and
significant thing to try - significant esp. for validating Laszlo's
abstractions. For now, xgrid.lzx is adequate for my needs; just making
it available as-is/in case others find it useful.

Yang