Refactored JS to work with clicking & mouseswheel

Based on test3 dev 5 (progress) from Daz
hrefs removed from nav's anchor tags, replaced with id's for the hooks
scrollToPosition now has if to error catching for no DOM elem
return false added to scrollToPosition to stop it deferring to native
(stops flicking/jumping)
Won't attempt to go past first or last post now on mousewheel use
Uses only position to track the position
Clicking uses same scrollToPosition function
Removed unused vars etc