1.3rc1 Selector compatibility

[canglan]

The altest 1.3rc1 breaks some of my existing code because the changes done in the selector.

From line 287:

` if ( this.length === 1 && !/,/.test(selector) ) {

var ret = this.pushStack( [], "find", selector ); ret.length = 0; jQuery.find( selector, this[0], ret ); return ret;

} else { ... `

[john]

This was confirmed as being an issue with the Validation plugin.