Extended binding-model-api to support of Enclosed Generated Types and TOs.

Extended binding-model-api to support of Enclosed Generated Types and TOs.

Added javadocs for whole binding-model-api project (including builders);
Refactored model structure for MethodSignature - added TypeMember interface which extracts common functionality for methods and properties.
MethodSignature and GeneratedProperty now extends TypeMember.
Added TypeMemberBuilder interface.

In Binding-generator-util project Refactored whole Building mechanism - removed code duplicities and added more abstraction layeres for abstract builders.
Automaticly modified all dependant project java files that uses binding-model-api.
Added isAbstract flag method into GeneratedType interface and setAbstract method into GeneratedTypeBuilder to notify if generated type (class) is declared as abstract.
Added isAbstract flag method into MethodSignature interface and setAbstract method into MethodSignatureBuilder to notify if generated method is declared as abstract.
Fixed bug (bad typecast) when resolving Identityref type definition in TypeProviderImpl in binding-generator-impl.

Added Support to generate Bits types - JG.

Change-Id: I983cdad79c8779940e75937f97ba0575e753830e
Signed-off-by: Lukas Sedlak <lsedlak@cisco.com>
Signed-off-by: Jozef Gloncak <jgloncak@cisco.com>