A few more tweeks after working out issues with implementation

added a postExposeCallback
improved the way elements are exposed
added expose tracking array to realign all (allowing for more than one) when window size changes
added needed call to methods.un_expose when ride ends.

fixed right side tip placement

fixed methods.corners to calculate based upon the final scroll_to location since the scroll_to likely hasn't finished when corners is being run. Also changed all the checks to allow corners to return false if alignment is equal, since false is what we want for placement

Change-Id: Iae7b2e322769bb661be41ec65ffe09b2791ffe36