add a test for an issue with null array members
first whack at a fix for aforementioned nulls being omitted when they shouldn't be
more thorough tests for excluding nulls given the recent troubles
serialization support for converting enums to different primitive types based on a new JilDirectiveAttribute parameter
deserialization support for converting integer primitive types to enum values based on JilDirectiveAttribute.SerializeEnumerationAs
better name for that enum property
fix some 'old code'-flag paths that have been broken over the last few weeks
and restore ideal paths
2.5.0