ensure that observers will  not override original object, ensure that multiple entries for the same observer does not appear in the observer or computed maps for a kind

Enyo-DCO-1.1-Signed-off-by: Cole Davis <cole.davis@lge.com>
add unit test for duplicate entries in computed and observer properties

Enyo-DCO-1.1-Signed-off-by: Cole Davis <cole.davis@lge.com>
Merge pull request #484 from enyojs/post-9-updates

Fix issue where multiple observers with same name were registered on objects through the inheritance mechanism

Reviewed-By: Ben Combee (ben.combee@lge.com)