Added alias of jQuery to $j - this is only to get site/user scripts that were using...

Added alias of jQuery to $j - this is only to get site/user scripts that were using $j to work. Use of $j should be phased out in favor of $. If you are writing a library that's intended for re-use, please wrap it in a closure that passes jQuery as $ such as "( function( $ ) { /* code here */ } )( jQuery );" so that people using alternative short names for jQuery can use the code unmodified.