The breakpoint manager now works -- breakpoints can be set from the main debugger...

The breakpoint manager now works -- breakpoints can be set from the main debugger or the manager

* English.lproj/Breakpoints.xib: Set the NSTableView's delegate to be File's Owner and disconnect the content IBO to the NS-AC
* Source/BreakpointManager.m:
(updateDisplaysForfile:): New private method
(addBreakpoint:): Call [updateDisplaysForfile:]
(removeBreakpointAt:inFile:): ditto
* BreakpointWindowController.m+h: Add props and synth them for sourceView and arrayController ivars
(removeBreakpoint:): Fill out method stub
(tableViewSelectionDidChange:): Implement delegate method
* DebuggerWindowController.m+h: Add prop/synth for sourceViewer ivar