Renamed File menu to Team and Quit to Close.

 There isn't actually a file on disk somewhere. And Quit
 could have been mistaken to quit the entire Debugger
 application, as Quit in File usually does with applications.
 However, it will only close the that team window and only
 quit Debugger if it was the last open window.
Changed hierarchy of splits to give variables/registers more room
Remove the spacing between menu bar and contents

 * The spacing is already present due to the insets
   of the contents, so there was some extra room
   between the menu and the contents which this
   commit removes.