Added Expose Feature

Implemented using the same method used by http://jquerytools.org/documentation/toolbox/expose.html. To use simply add "expose" to the "data-options" attribute to one of your tour outline stops including a comma separated list of the items (other than the tip ofcourse) that you wish to expose.

For example:
````<li data-id="someID" data-options="expose : #exposeThisElm, .AndThisElm">````