created new JsonBuildException
large commit with outline of Json serialization
Squished warning
refactored JsonBuilder<T> into JsonDocumentBuilder<T> and
JsonFragmentBuilder
added JsonValueSerializationApproach
renamed JsonSerializationApproach subclasses
added JsonValueJsonSerializationApproach to DefaultJsonSerializer
made AbstractJsonSerializer abstract
added CustomizableJsonSerializer
added better tests for serialization
renamed JsonSerializationApproach to JsonSerializeApproach
renamed method to match JsonSerializeApproach names