Debugger: Fix memory display

- Watchwindow: Do not open Address dialog if menu is canceled (act = 0
  matching the unitialized unknown memory action)
- Actually pass the address of the dialog to the agent
- Make the "Open Memory editor..." action always visible to be able to
  look at const char *x pointing at y
- Improve the address dialog with checking and dialog button box
- Explicitly pass the quint64 around
- Translate & purge

src/plugins/debugger/cdb/cdbdebugengine.h

@@ -89,6 +89,7 @@ public:
 
     virtual void fetchDisassembler(DisassemblerViewAgent *agent,
         const StackFrame &frame);
+    virtual void fetchMemory(MemoryViewAgent *, quint64 addr, quint64 length);
 
     virtual void reloadModules();
     virtual void loadSymbols(const QString &moduleName);