Fixed the remaining join variations, (left, right, natural, etc).
(Previous fix only solved "," and "[cross] join".)


mysql-test/r/select.result:
  Added more test case results for more braced join fixes.
mysql-test/t/select.test:
  Added more tests for braced join fixes.
sql/sql_yacc.yy:
  Changed the remaining join_table_list cases to handle braces.
  Also added some precedence declaration to silence shift/reduce conflicts
  warnings that turned up after these fixes.