Avoid for-in loops with explicity copied keys
use shared WeakMap repo
fix karma paths for WeakMap
Put pointermap back, remove sidetable reference
Merge pull request #102 from azakus/faster-constructor

Faster constructor and Event cloning
Set buttons to undefined by default to catch lack of event.buttons support in PointerEvent constructor

Need to copy event.which to facilitate this
Only set primary touch pointer when there are no other touches

removePrimaryTouch broken by removing extraneous touch identifier cloning
Fixes Polymer/PointerGestures#15
remove sourcemap from build, it was always off by a few lines