Reorganized core type fields in a subdirectory.
fix: 'es_' prefixed kwargs are ignored in custom mapping if they already exist in _mapping_options. feature: serialize and deserialize are existing for all fields. Implemented as an identity by default
fix: ip to int / int to ip based on the serialize/deserialize feature.
feature: custom exceptions
feature: add a get to access fields
use Fields.get()
simplification of the custom JsonEncoder.