Enum Support & Pick up Row from Table

• Added get_row which picks up a row of a table at the specified index as a dictionary
• Added ENUM_ATOM and ENUM_LIST type indicator.
• Added new_enum to api.
• get_long in api supports enum
• get_row in api takes source enum names to support enumerated table
• push_raw in api supports enum
• len in api supports enum
  Note: enum type is not self-completed in C API because source symbol list is not contained in the enum K object