Upgrade knockout to 3.2.0

https://github.com/knockout/knockout/releases/tag/v3.2.0
Update CHANGES.md
Merge remote-tracking branch 'origin/master' into knockout-3.2.0

Conflicts:
	CHANGES.md
Merge remote-tracking branch 'origin/master' into knockout-3.2.0

Conflicts:
	CHANGES.md
Merge branch 'master' into knockout-3.2.0

Conflicts:
	CHANGES.md
Merge pull request #2198 from AnalyticalGraphicsInc/knockout-3.2.0

Upgrade knockout to 3.2.0
Merge remote-tracking branch 'origin/master' into detached-referenceProperty

Conflicts:
	CHANGES.md