Changes

Summary

1. Fixes #2174 New method copyWithoutDuplicates. First naive (details)

Commit 0f38c33add42aabba93bce6f0683e0d22db1c5e2 by hilaire Fixes #2174 New method copyWithoutDuplicates. First naive implementation.
	src/Collections-Abstract/Collection.class.st (diff)
	src/Collections-Tests/CollectionTest.class.st (diff)