Default value for depth/cut now positive. Added note to tooltip.

FlatCAMObj.py

@@ -1028,7 +1028,7 @@ class FlatCAMGeometry(FlatCAMObj, Geometry):
             "paintmargin": 0.01,
             "paintmethod": "standard",
             "multidepth": False,
-            "depthperpass": -0.002
+            "depthperpass": 0.002
         })
 
         # Attributes to be included in serialization

ObjectUI.py

@@ -299,7 +299,7 @@ class GeometryObjectUI(ObjectUI):
 
         maxdepthlabel = QtGui.QLabel('Depth/pass:')
         maxdepthlabel.setToolTip(
-            "Depth of each pass."
+            "Depth of each pass (positive)."
         )
         grid1.addWidget(maxdepthlabel, 6, 0)
         self.maxdepth_entry = LengthEntry()