Merge pull request #1167 from aspectit/scrollTop-new

Fix mouse handling inside a scrollable div.
Merge pull request #1171 from aspectit/eventjs

Stop Event.js from messing with global Event objects.
Speed up getElementStyle
Add JSCS validation & change bunch of things for conformance. Down to 333 failures from ~1000.
Add jscs as a dev dependency
Update package.json
Make mouse handling respect CSS scaling.

Also DRYs getPointer() calls in many places.

See #868.
Also consider CSS transforms when handling mouse.