Fixes #1041, Android WebView triggers two clicks at once. This calls
L.DomEvent.stop(event) on the second if two clicks are triggered within 400ms
of each other. Double click is unaffected however.

There are other workarounds that focus on _fireMouseEvent(), however I had to
resolve it at the click event level as my map, markers, controls, were all
affected.
This makes sure we only do the Android duplicate click workaround on Android
This modifies the Android WebView phantom click workaround.
Previously it was blocking when an element had multiple click listeners
because those events were fired rapidly. Since Android fires its second
click at approximately 300ms after the first we do a check to make sure
that at least 100ms has elapsed but not more than 400ms.
Merge pull request #1227 from jerel/patch/android-webview

A bug in Android WebView triggers two clicks at once.