fix multitouch issues

send correct infos when two or more pointers are detected
send different events if needed (move + touchstart)

what was buggy : 

case 1 :
1. finger 1 => move
2. finger 2 => tap 
====> no touchend nor touchstart detected and neither triggered for finger 2

case 2 : 
getX getY werent attached to their pointerId so, bad informations sent (always pointer 1 x and y)