Update site.js

Encapsulated jQuery to prevent conflicts with Sitecore and other JS libraries that may fight over the use of '$'. Added a missing semi-colon to line 34. Passed in $siteNav as a context for the $subnavTrigger and $subnav variables to improve selector performance (so jQuery doesn't have to traverse the entire DOM).
Merge pull request #1 from dthunziker/patch-1

Update site.js