Critical Debugger Bugfix, Docking Bugfix

Build 0.9.9.310, 25 Nov 2001:
-Debugger: StepOver a chdir command has crashed the debugger - fixed.
-Docking: The following docking sequence has lead to a General Protection Fault - fixed.
1) HelpViewer has been docked to a page control. The help viewer has shown a document.
2) The hosting page control has been docked to another location. The redraw has not been done correctly.
3) Finally, undocking the page control has raised the error.