Prevent "ghost click" phenonenoms

Ghost clicks occur when an element is removed before the 300ms delayed click event is fired, but the click event is
still sent.
This click event will be sent to whatever is now on top at that coordinate.
move sample to test folder as a manual test
Merge pull request #73 from Polymer/ghostclick

Prevent "ghost click" phenonenoms
Make sure to use event path for gesture spinup if available on iOS

Add manual test (for ios with shadowdom polyfill)

Fixes #76 on iOS, <content on-tap="{{...}}"> doesn't work
add manual test for ghost focus
added editorconfig
Ported flick
flick migration
image demo
working demo
prevent image from dragging