Delete from table using join to another table

[luksrn]

Support for parse delete from table using join to another table like:

DELETE posts
FROM posts
INNER JOIN projects ON projects.project_id = posts.project_id
WHERE projects.client_id = :client_id

This necessitated some changes to the DeleteTest class, specifically:

JSqlParserCC.jjt - changes on grammar of Delete statements.
Delete toString and DeleteDeParser.

[coveralls]

Coverage increased (+0.1%) to 83.883% when pulling b6eb57b on luksrn:delete_from_table_using_join_to_another_table into 1b1655c on JSQLParser:master.

[luksrn]

I was thinking of treating the specific situation of Postgres (using instead join) in a second pull request , but decided to send this before to get some feedback necessary . Even if this request will be approved.

DELETE FROM films USING producers
WHERE producer_id = producers.id AND producers.name = ' foo' ;