Initial work on ERRAI-621: incremental marshaller generation
Removed unnecessary debug output
Progress on ERRAI-621: Introduced custom type specific marshaller generator (not executed yet)
Added support for declaring inner classes to ClassStructureBuilder
minor formatting change in class generator to save lines
Progress on ERRAI-621: MarshallerFactory refactored and triggering deferred generation of custom marshallers

- custom marshaller generator not ready yet
Progress on custom marshaller generator for ERRAI-612

- first set of tests passing (missing deferred generation of array marshallers on client)
Progress on ERRAI-621: Deferred array marshalling working
ERRAI-621: All serialization tests passing using deferred generators
Adding com.google.gwt.* to implicit type whitelist
Allow for portable types with underscores in class name
Fixed code gen assertions to reflect shorter representation of empty classes
No longer consider lazy built-in marshallers for client-side (not needed anymore)

- all test passing using Maven now as well
Introduced lazy init. method for nested marshallers to avoid initialization cycles
Fixed compilation error in ObserversMarshallingExtension.java
Private field accessor methods now need to be generated for each marshaller class
Check for null PrintWriter (in case class was already generated)
Ensured nested marshaller fields are created for inherited built-in mappings
Merge branch 'inc-marshaller-gen'