[Lazarus] Insufficient keyboard modifiers support in IDE

[Alexey]

 >Both in Lazarus v1.7 and v1.9 using the IDE compiled with LCL-GTK2.

Check "Meta" shows on Mac only; you need it for Lin/Win? It is simple 
fix, one liner.

function TCustomShortCutGrabBox.GetDefaultShiftButtons: TShiftState;
begin
   {$IFDEF Darwin}
   Result:=[ssCtrl,ssShift,ssAlt,ssMeta];
   {$ELSE}
   Result:=[ssCtrl,ssShift,ssAlt];
   {$ENDIF}
end;

-- 
Regards,
Alexey