Improve IE 10 pointer capture

IE 10 uses a concept of pointer capture to allow elements to continue
receiving events when the pointer moves outside them; it turns out
pointer capture isn't exclusive, so always request it to prevent
cancel/end events from being lost in edge cases.  Fixes loss of
responsiveness on IE 10.
Fire scrollstart event for animated scrollBy() and scrollTo() calls

Improve scrollTo() logic (which also handles scrollBy) to fire the
scrollStart event if an animated scroll is being triggered, to allow
the UI to react appropriately if necessary.  Also improve smartness of
_hasBeenScrolled tracking to only record actual scrolls within
scrollTo().
Add lax whitespace to the jslint options

Unconvinced by anti-tab arguments
Add support for reachedstart/reachedend events (#15)

Pull #15 requested reachedstart and reachedend events, together with an
example showing their use; this commit re-implements those events in a
different manner to allow flings to correctly fire the events at
approximately the right time.
Add support for alwaysScroll instance option

Allow use of an alwaysScroll instance option to force the scroller to
always allow scrolling/bouncing, even if there would be insufficient
content to normally trigger scrolling.  Roughly equivalent to changing
overflow: auto to overflow: scroll.
Update copyright date
Improve nested scroller drawing and responsiveness

 - Split the old scrollBoundary option into two: scrollBoundary
(handles exclusive scrolling/locking boundary) and
scrollResponseBondary (handles when updates are drawn in response to
touches)
 - Set the default scrollResponseBoundary to 1, and add support for
drawing updates while still able to cancel the scroll if another
scroller gains scroll lock
 - Improve IE 10 nested scrollers.  (Known issue: pointer capture is
cancelled on one element if another element captures pointers, causing
problems in nested scrollers)
 - Add boundary examples to the Gallery scrollers example, and improve
the example
Fix IE 10 input issues, possibly addressing the last part of #18
Update README to include reachedStart/reachedEnd events

Document the reachedStart and reachedEnd events added in
543cca767e5f5063e14e09c2d6a13ed9723284ab, completing #14.
Merge in changes from master, tweak linting

Merge in the changes from master, and amend linting to keep use of
jslint rather than jshint; tweak things jslint complains about