Set dev version
None is None!
Fix work with empty containers
Small fix
Allow None in EmbeddedDocumentField
Allow None in DecimalField
Add fields.money for work with money
Some fixes in money
Work FieldDescriptor.load_deferred with embedded documents
Use from_mongo in EmbeddedDocumentField.from_mongo instead **kwargs
Use direct set document.__data__[name] instead setattr in from_mongo
Remove accept int in MoneyField.prepare_value
Refactoring containers
Some small refactoring
Add MapField
Cancel xor, mod and divmod operators for Money
Refactoring for DatetimeField
Add EmailField
Fix import EmailField
Some small fixes