Simple-ddl-parser

1. Added support for REFERENCES without field name, like `product_no integer REFERENCES products ON DELETE RESTRICT`
2. Added support for REFERENCES ON statement

1. Added support for HQL Structured types like ARRAY < STRUCT <street: STRING, city: STRING, country: STRING >>,
MAP < STRING, STRUCT < year: INT, place: STRING, details: STRING >>,
STRUCT < street_address: STRUCT <street_number: INT, street_name: STRING, street_type: STRING>, country: STRING, postal_code: STRING >

1. To DDLParser's run method was added 'output_mode' argument that expect valur 'hql' or 'sql' (by default).
Mode change result output. For example, in hql exists statement EXTERNAL. If you want to see in table information
is it EXTERNAL table or not - you need to set 'hql' output_mode.
2. Added support for hql EXTERNAL statement, STORED AS statement, LOCATION statement
3. Added support for PARTITIONED BY statement (for both hql & sql)
4. Added support for HQL ROW FORMAT statement, FIELDS TERMINATED BY statement, COLLECTION ITEMS TERMINATED BY statement, MAP KEYS TERMINATED BY statement

1. Fix behaviour with -- in strings. Allow calid table name like 'table--name'

1. Added support `/* ... */` block comments
2. Added support for Mysql '' comments

1. Ignore inline with '--' comments