Fix cross2Line() for ray lines.
Draw the limit box.
Fix MgCommandDraw::_initialize().
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().
Fix mglnrel::clipLine().
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.
Send shapeChanged notify in MgCommandDraw::touchMoved().
Add mgstrcallback.h
Change the parameter type of onShapeAdded.
Add a parameter of onDocLoaded.
Add 'startMustVertex' option.
Add 'snapTangent' option.
Fix MgLocalized::getString() and snapping functions.
Add 'canBoxSel' option.
Add MgMotion parameter of setStepPoint.