Added: influences mapping in mirror screen will now allow matching joints by DG connections; if symmetrical joints are
linked between themselves with message connections, ngSkinTools will be able to leverage that information when
mirroring weights;
Added: symmetry mesh: an option to provide an alternative mesh for calculating vertex mapping for mirroring;
Fixed: deleting visibility node can crash maya sometimes, e.g. switching to component mode (F8) while paint tool is active