Added ENotifyKeypresses and ECaptureCtrlC flags to CCommandBase. Commands can now get keypresses and handle ctrl-C via callbacks instead of having to implement custom active objects. As part of this extended the CCommandBase extension interface to MCommandExtensionsV2 for the new virtual functions KeyPressed(TUint aKeyCode, TUint aModifiers) and CtrlCPressed(). sudo now cleans up correctly by using ECaptureCtrlC.