Added: Persistence FieldType interface and implementation
Added: FieldType registry
Added: FieldType registry to settings.ini and Legacy Handler
Added: register() method
Added: getFieldTypeRegistry() method
Updated: SPI FieldType integration tests use FieldTypeRegistry
Tested: FieldTypeRegistry
Fixed: returning object instance
Added: FieldTypeRegistry to buildLegacyEngine()
Added new test suite to the configuration
Fixed funny code flow
Fixed phpdoc, changed property name
Tested: Handler::getFieldTypeRegistry()
Merge pull request #205 from ezsystems/PersistenceFieldType

FieldType interface for usage in Storage Engines