Update support,rb to handle cusom serializers

Write value that model returns to cache instead of supplied value. This way, if a custom serializer changes the type of the object, the returned value from the cache will match.
Bump version number
Add test for serialization change
Add custom serializer to test_models.rb
Move serialize method so class id defined
Merge remote-tracking branch 'ser/master'
added a comment and a CHANGELOG entry