Avoid to snap points same as the start point of the current line.
Add getSubType, shapeWillDelete and getShapeIndex.
Add bringToIndex() and reorderShapes().
Ignore the value from getLockSelShape() if 'id' has been assigned.
Add 'name' field of MgGroup. Skip hidden shapes in hitTest.
Add isVisible() and isLocked().
Merge branch 'r52' into develop

'Vertext' -> 'Vertex'.
Add ignoreStartPoint() for commands.
Add getSubType(), isVisible() and isLocked() for shapes.
Add name field of group shapes.
Add bringToBack(), bringToIndex(), getShapeIndex() and getShapeAtIndex() of MgShapes.
Add shapeWillDelete notify.