CVS commit by jriddell: Added undo and redo feature M +51 -29 uml.cpp 1.13 M +35 -5 uml.h 1.3 M +149 -27 umldoc.cpp 1.6 M +66 -7 umldoc.h 1.3 M +16 -4 umlview.cpp 1.16 M +0 -2 umlviewdata.cpp 1.5 M +8 -5 umlwidget.cpp 1.8