Introduced CompositeNode <-> NormalizedNode serializer


- add AnyXmlNodeBase parser and serializer
- in ContainerNodeCnSnSerializer and MapEntryNodeCnSnSerializer was used
MutableCompositeNodeTOImpl which uses init() method which is deprecated
therefore it was rewritten and also whole package was renamed.
- support for AnyXml yang type to yang-data-composite-node

Change-Id: I1f40beef29e8c1c052113043f7029fbc0650192c
Signed-off-by: Tony Tkacik <ttkacik@cisco.com>
Merge "Introduced CompositeNode <-> NormalizedNode serializer"