MouseTracker original events in handlers

Implemented "Expose original event in handlers" (#23) for MouseTracker

Added OpenSeadragon.getElementOffset() method. Element-relative mouse
coordinates should be correct even if the element and/or page is
scrolled (#131)
MouseTracker Original Events in handlers

Comment & Formatting fixes
MouseTracker Original Events in Handlers

More formatting fixes
MouseTracker Original Events in Handlers

More formatting fixes
MouseTracker Original Events in Handlers

Bug fixes.  Event handler methods shouldn't be called directly in
theory...
MouseTracker Original Events in Handlers

Pass original touch events to handlers.
MouseTracker Original Events in Handlers

Misc name changes, indentation/whitespace fixes.
Still TODO: Fix documentation, evaluate presence of key handler in a
mouse tracker, evaluate whether isTouchEvent flag should be in all
eventData objects or not.
MouseTracker Original Events in Handlers

Touch events bug fix. Now uses touch object(s) properly when calculating
positions.
MouseTracker Original Events in Handlers

Renamed insideElementRelease to insideElementReleased.
Original Events in Handlers

Documentation fixes
isTouchEvent property removed from eventData where not used
'eventOrTouchPoint' var name used and 'originalEvent' var name restored
to 'event'
MouseTracker Original Events in Handlers

MouseTracker Unit Tests
MouseTracker Original Events in Handlers

changelog.txt update
MouseTracker Original Events in Handlers

Whitespace fixes on un-empty [] brackets
MouseTracker Original EVents in Handlers

changelog.txt fixed issue reference numbers (#23) (#215)
changelog.txt update for fixed issue #131
Merge branch 'Original-Events-In-Handlers' of github.com:msalsbery/openseadragon into msalsbery-Original-Events-In-Handlers

Fixed Conflicts:
	changelog.txt