Fix bugs and improve trackpad scroll precision

Improve trackpad precision by making the amount
of scroll, flickVelocity and flickDeceleration
proportional

src/gui/Base/HFlickable.qml

@@ -4,16 +4,8 @@ import QtQuick 2.12
 import QtQuick.Controls 2.12
 
 Flickable {
-    id: flickable
     interactive: contentWidth > width || contentHeight > height
     ScrollBar.vertical: ScrollBar {
-        visible: flickable.interactive
-    }
-
-
-    readonly property HTrackpadFix trackpadFix: HTrackpadFix {
-        flickable: flickable
-        width: flickable.width
-        height: flickable.height
+        visible: parent.interactive
     }
 }