fix(gestures): improve drag/swipe response

Fixes #1729, #2674

Author: adamdbradley

Diff for: js/utils/gestures.js

@@ -1108,7 +1108,7 @@
     defaults: {
       // set 0 for unlimited, but this can conflict with transform
       swipe_max_touches  : 1,
-      swipe_velocity     : 0.7
+      swipe_velocity     : 0.4
     },
     handler: function swipeGesture(ev, inst) {
       if(ev.eventType == ionic.Gestures.EVENT_END) {
@@ -1164,6 +1164,15 @@
     },
     triggered: false,
     handler: function dragGesture(ev, inst) {
+
+      if (ev.srcEvent.type == 'touchstart' || ev.srcEvent.type == 'touchend') {
+        this.preventedFirstMove = false;
+
+      } else if (!this.preventedFirstMove && ev.srcEvent.type == 'touchmove') {
+        ev.srcEvent.preventDefault();
+        this.preventedFirstMove = true;
+      }
+
       // current gesture isnt drag, but dragged is true
       // this means an other gesture is busy. now call dragend
       if(ionic.Gestures.detection.current.name != this.name && this.triggered) {