Working around an extremely annoying apple bug in NSTreeController and an NSOutlineVi...

Working around an extremely annoying apple bug in NSTreeController and an NSOutlineView. When the contentArray is bound on an NSTreeController, the observing can go haywire and just crash randomly.

* English.lproj/Debugger.nib: Unbinding RegisterController's content array
* Source/DebuggerConnection.m:
([DebuggerConnection registerRecieved:]): Sending [_windowController setRegister:] the entire document instead of the rootElement
* Source/DebuggerWindowController.h: Removed _register ivar and changed setRegister: to take an NSXMLDocument
* Source/DebuggerWindowController.m:
([DebuggerWindowController setRegister:]): Instead of changing a property and letting KVO do the work (and subsequently and randomly crash), force the controller to have new content