Clip boundary commands: remove requirement for TrackPanel to be focus

When these commands were initially written, they operated on the focused track. This is no longer the case, so I've remove the requirement for the TrackPanel to be the focus.

src/Menus.cpp

@@ -674,14 +674,14 @@ void AudacityProject::CreateMenusAndCommands()
       c->BeginSubMenu(_("Clip B&oundaries"));
       c->AddItem(wxT("SelPrevClipBoundaryToCursor"), XXO("Pre&vious Clip Boundary to Cursor"),
          FN(OnSelectPrevClipBoundaryToCursor), wxT(""),
-         TrackPanelHasFocus | WaveTracksExistFlag, TrackPanelHasFocus | WaveTracksExistFlag);
+         WaveTracksExistFlag, WaveTracksExistFlag);
       c->AddItem(wxT("SelCursorToNextClipBoundary"), XXO("Cursor to Ne&xt Clip Boundary"),
          FN(OnSelectCursorToNextClipBoundary), wxT(""),
-         TrackPanelHasFocus |WaveTracksExistFlag, TrackPanelHasFocus | WaveTracksExistFlag);
+         WaveTracksExistFlag, WaveTracksExistFlag);
       c->AddItem(wxT("SelPrevClip"), XXO("Previo&us Clip"), FN(OnSelectPrevClip), wxT("Alt+P"),
-         WaveTracksExistFlag | TrackPanelHasFocus, WaveTracksExistFlag | TrackPanelHasFocus);
+         WaveTracksExistFlag, WaveTracksExistFlag);
       c->AddItem(wxT("SelNextClip"), XXO("N&ext Clip"), FN(OnSelectNextClip), wxT("Alt+N"),
-         WaveTracksExistFlag | TrackPanelHasFocus, WaveTracksExistFlag | TrackPanelHasFocus);
+         WaveTracksExistFlag, WaveTracksExistFlag);
 
       c->EndSubMenu();
       /////////////////////////////////////////////////////////////////////////////
@@ -887,9 +887,9 @@ void AudacityProject::CreateMenusAndCommands()
          TracksSelectedFlag, TracksSelectedFlag);
 
       c->AddItem(wxT("CursPrevClipBoundary"), XXO("Pre&vious Clip Boundary"), FN(OnCursorPrevClipBoundary), wxT(""),
-         TrackPanelHasFocus | WaveTracksExistFlag, TrackPanelHasFocus | WaveTracksExistFlag);
+         WaveTracksExistFlag, WaveTracksExistFlag);
       c->AddItem(wxT("CursNextClipBoundary"), XXO("Ne&xt Clip Boundary"), FN(OnCursorNextClipBoundary), wxT(""),
-         TrackPanelHasFocus | WaveTracksExistFlag,  TrackPanelHasFocus | WaveTracksExistFlag);
+         WaveTracksExistFlag, WaveTracksExistFlag);
 
       c->AddItem(wxT("CursProjectStart"), XXO("&Project Start"), FN(OnSkipStart), wxT("Home"));
       c->AddItem(wxT("CursProjectEnd"), XXO("Project E&nd"), FN(OnSkipEnd), wxT("End"));