Prevent Duplicating Behaviors

Hello,

I have been having an issue with gantt crashing browsers when using ajax within a form that is on the same page that the gantt is on.

The reason why this is causing the problem is that much of the gantt operations are wrapped in a behavior, which is great, however behaviors are attached to each ajax call and since gantt.init and gantt.load are pretty expensive javascript calls it causes the browser to crash.

I have a patch that wraps all that is within the behavior in jquery.once. While I haven't fully tested this it seems to be resolving my issue.

Let me know if there are any problems with this approach. We could take some of the javascript out so it can be fired more but there doesn't seem to be anything that needs to be fired more than once from first glance.

-Jesse