remove vertex selection check for weight paint mode so you can paint through the mesh.

also made the wire draw without depth masking when the depth check is off, similar to mesh editmode drawing, nice hint about whats going on.

release/scripts/startup/bl_ui/space_view3d.py

@@ -71,7 +71,7 @@ class VIEW3D_HT_header(Header):
 
             # Occlude geometry
             if ((view.viewport_shade not in {'BOUNDBOX', 'WIREFRAME'} and (mode == 'PARTICLE_EDIT' or (mode == 'EDIT' and obj.type == 'MESH'))) or
-                    (mode == 'WEIGHT_PAINT' and obj.data.use_paint_mask_vertex)):
+                    (mode == 'WEIGHT_PAINT')):
                 row.prop(view, "use_occlude_geometry", text="")
 
             # Proportional editing