"PRIMARY" has been replaced by primary_key_name.


sql/mysql_priv.h:
  "PRIMARY" replaced by primary_key_name.
sql/sql_help.cc:
  "PRIMARY" replaced by primary_key_name.
sql/sql_select.cc:
  "PRIMARY" replaced by primary_key_name.
sql/sql_show.cc:
  "PRIMARY" replaced by primary_key_name.
sql/sql_table.cc:
  fix for the 2361 bug: ALTER TABLE ... DROP PRIMARY KEY drops a non-primary key
  "PRIMARY" replaced by primary_key_name.
sql/table.cc:
  "PRIMARY" replaced by primary_key_name.