Fix for discount bug 5913

Fix Itm discount bug https://bugs.oxid-esales.com/view.php?id=5913
Merge pull request #172 from revoltek-daniel/patch-7

Fix for discount bug 5913
Added basket integration test case for bug #5913
Merge remote-tracking branch 'oxid/b-dev-ce' into composer

Conflicts:
	tests/unit/views/oxviewconfigTest.php
Merge branch 'composer' of https://github.com/robinlehrmann/oxideshop_ce into composer