Refactor startHammer

[kurkle]

• split startHammer into three parts
• remove the _ghostClickHandler that would mask the click event on pan end of the canvas
  • this must have somehow been inserted before chart event listeners in v2
  • add similar logic in beforeEvent to mask the click

Resolves: #441

[Koxx3]

hello,
sorry, but I still struggle with scrolling pages with chartjs & zoom plugin.
can you explain the important options to enable page scrolling (and allow pinch zoom) please ?

[marttheis]

Hello,

I am also still having the problem that scroll gestures are eaten by chartjs when done on the chart. I am using
Chartjs 4.3.0
zoom plugin 2.0.1
hammerjs 2.08

It doesn't work.