Change qml double usage to real

Change-Id: Ic330f878cc573944d52743eaf02c56a0f303f866

qml/Gravity.qml

@@ -15,7 +15,7 @@ Item {
 
     QtObject {
         id: d
-        property double pace: settings.pace/60.0
+        property real pace: settings.pace/60.0
         property int itemCount: 0
         property int itemTravel: settings.itemTravel
         property int primedColumns: 0

qml/main.qml

@@ -15,11 +15,11 @@ Window {
         property int itemTravel: 1
         property int columnCount: 30
         property int interval: 2
-        property double pace: 1.0
+        property real pace: 1.0
         property bool viewItemCount: false
         property bool globalWorld: false
         // Very computationally heavy: 40% vs 20% for 0.1 vs 0
-        property double restitution: 0.1
+        property real restitution: 0.1
         property bool embossEffect: false
     }