Parser rejects ODBC's escape sequences for outer joins other
than left outer join, yet the escape sequence BNF specifies
that this syntax can be used for left, right, and full outer
join syntax.

The problem is that although the MySQL Connector/ODBC advertises
"Outer Join Escape Sequence" capabilities, the parsing is done
in the server and historically it only supported this syntax
for left outer joins and applications such as Crystal Reports
11 tries to use this syntax for inner joins.

The chosen solution is to reorganize a couple of parser rules
to ignore any kind of SQL escape sequence. Ignoring the escape
sequences is harmless because the various SQL join clauses
are supported by the server.


mysql-test/r/parser.result:
  Add test case result for Bug#28317
mysql-test/t/parser.test:
  Add test case for Bug#28317
sql/sql_yacc.yy:
  Reorganize rules in order to ignore SQL Escape Sequences