Fixed #100 cyclic garbage in TraitChangeNotifyWrapper
Update trait_notifiers.py

Clarified comments about cyclic garbage (issue #100)
Added changelog entry
Merge branch 'master' into fix-cyclic-garbage-TraitChangeNotifyWrapper

Conflicts:
	CHANGES.txt
Added full stop to comment
Merge pull request #101 from enthought/fix-cyclic-garbage-TraitChangeNotifyWrapper

Fixed #100 cyclic garbage in TraitChangeNotifyWrapper