Marcel Taeumel uploaded a new version of ST80 to project The Trunk:
http://source.squeak.org/trunk/ST80-mt.206.mcz

==================== Summary ====================

Name: ST80-mt.206
Author: mt
Time: 4 May 2016, 1:35:41.04699 pm
UUID: 69676c6d-8920-3746-a21f-d63502700535
Ancestors: ST80-dtl.205

Consistently with Morphic's system windows, allow models to close windows also in MVC.

=============== Diff against ST80-dtl.205 ===============

Item was changed:
  ----- Method: StandardSystemView>>update: (in category 'updating') -----
  update: aSymbol
  	aSymbol = #relabel
  		ifTrue: [^ self setLabelTo: model labelString].
+ 	aSymbol = #close
+ 		ifTrue: [^ self controller closeAndUnscheduleNoTerminate].
+ 		
  	^ super update: aSymbol!