Merge branch '2.3' of github.com:Ultimaker/Cura into 2.3

resources/definitions/fdmprinter.def.json

@@ -3764,6 +3764,7 @@
                     "type": "float",
                     "unit": "mm",
                     "default_value": 3,
+                    "value": "machine_nozzle_head_distance",
                     "minimum_value": "0.0001",
                     "maximum_value_warning": "20",
                     "enabled": "wireframe_enabled",

resources/qml/MonitorButton.qml

@@ -4,6 +4,7 @@
 import QtQuick 2.2
 import QtQuick.Controls 1.1
 import QtQuick.Controls.Styles 1.1
+import QtQuick.Dialogs 1.1
 import QtQuick.Layouts 1.1
 
 import UM 1.1 as UM
@@ -160,7 +161,7 @@ Rectangle
         anchors.rightMargin: UM.Theme.getSize("default_margin").width
 
         text: catalog.i18nc("@label:", "Abort Print")
-        onClicked: Cura.MachineManager.printerOutputDevices[0].setJobState("abort")
+        onClicked: confirmationDialog.visible = true
 
         style: ButtonStyle
         {
@@ -216,6 +217,18 @@ Rectangle
         }
     }
 
+    MessageDialog
+    {
+        id: confirmationDialog
+
+        title: catalog.i18nc("@window:title", "Abort print")
+        icon: StandardIcon.Warning
+        text: catalog.i18nc("@label", "Are you sure you want to abort the print?")
+        standardButtons: StandardButton.Yes | StandardButton.No
+        Component.onCompleted: visible = false
+        onYes: Cura.MachineManager.printerOutputDevices[0].setJobState("abort")
+    }
+
     Button
     {
         id: pauseResumeButton