remove auto_screenshot argument of Viewer.__init__()
remove auto_screenshot argument of Viewer.__init__()

- update .call_mlab()

BubuLK/sfepy,rc/sfepy,sfepy/sfepy,lokik/sfepy,BubuLK/sfepy,lokik/sfepy,RexFuzzle/sfepy,sfepy/sfepy,lokik/sfepy,RexFuzzle/sfepy,lokik/sfepy,vlukes/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,vlukes/sfepy,sfepy/sfepy,vlukes/sfepy,rc/sfepy,RexFuzzle/sfepy,rc/sfepy