Shouldn't warn about CCK date configuration on event nodes

Initial patch -- this at least suppresses the warnings on the content admin pages.

However, I wonder if we should also:

A) Hide the "Date field to use with signup" field entirely on node types that are event enabled.

or

B) Put "event module" or something into that list and select it by default on event-enabled nodes.

?

Here's a patch that updates the jQuery code to only show the "Date field to use with signup" setting if a node type is not event-enabled (option A above). There might be a cleaner way to do this than two separate AutoAttach functions, one for each setting (event-enable and signup-enable), but this is working fine, both with and without event.module enabled.

Simplified the jQuery by combining the two functions into a single one that notices if either radio is clicked, and then checks the current state of both sets to decide what to do. Thanks, sun. ;)

Committed to HEAD and DRUPAL-5--2.