More work on descriptor_storage - buffer based storage is complete. Added dispatch table jdksavdecc_descriptor_storage_symbols to manage efficient dispatch tables for symbols for specific aecp_message_types, aem_command_type, and symbol.
Added entity_model class for access to configuration count and read descriptor as an abstract base class for descriptor_storage and descriptor_storage_gen. Modified entity_manager and controller_manager to use the entity_model.
Merge branch 'minimal-devel' of github.com:jdkoftinoff/jdksavdecc-c into minimal-devel