This fix corrects build issues introduced by WL#3031:

- In the SQL grammar, 'USER' is a SQL 2003 reserved keyword,
and therefore should not be part of the keyword production.

- In sql/sql_parse.cc, the code for CREATE SERVER and ALTER SERVER
was not using proper format strings in the DBUG_PRINT statements.


sql/sql_parse.cc:
  Fixed compiler warnings
sql/sql_yacc.yy:
  Fixed reduce/reduce conflicts