Example 4 - Save the state
If you set the option saveState to true, then jqtree remembers the tree state after a page reload.
JqTree save the state into localStorage.
If the browser does not support localStorage, then jqTree saves the state in a cookie.
You must include the jquery-cookie plugin for cookie support.
Giving the saveState a string value sets the storage key. The default key is 'tree'.