OGM-428 Introducing OptionValueSource SPI
OGM-428 Making programmatic and annotation option sources return immutable option containers
OGM-428 Allowing to read options specified via configuration property through OptionsService;

Using this for MongoDB's write concern
OGM-428 Reading more option types through OptionsService when given via configuration property
OGM-428 Caching OptionContexts in OptionServiceImpl