Show all generated warnings in SHOW ERROR

Previously we only stored the first given error (the error sent to the client)


include/mysys_err.h:
  Moved ER_FILENOTFOUND last to avoid getting 'error 0'
mysql-test/r/backup.result:
  More warnings from in case of errors
mysql-test/r/innodb.result:
  More warnings from in case of errors
mysql-test/r/key_cache.result:
  More warnings from in case of errors
mysql-test/r/myisam.result:
  More warnings from in case of errors
mysql-test/r/preload.result:
  More warnings from in case of errors
mysql-test/r/repair.result:
  More warnings from in case of errors
mysql-test/r/rpl_failed_optimize.result:
  More warnings from in case of errors
mysql-test/r/subselect.result:
  More warnings from in case of errors
mysql-test/t/backup.test:
  Portability fix
mysql-test/t/innodb.test:
  Avoid some warnings
mysql-test/t/myisam.test:
  Portability fix
mysql-test/t/rpl_rotate_logs.test:
  Portablitiy fix
mysys/errors.c:
  Move ER_FILENOTFOUND last to avoid error 0
sql/mysql_priv.h:
  Indentation change
sql/mysqld.cc:
  Save all given errors for SHOW ERRORS
sql/protocol.cc:
  Store new errors for SHOW ERROR
  (Ignore those that are already reported with my_error())
sql/sql_class.cc:
  More errors with SHOW ERROR
sql/sql_class.h:
  More errors with SHOW ERROR
sql/sql_error.cc:
  More errors with SHOW ERROR
sql/sql_parse.cc:
  Temporary fix: Don't give error for the to-be-removed 'pre-open tables code'
sql/sql_show.cc:
  More debugging
  Don't register errors while populating schema tables.
  (If we do, we get a LOT of warnings from information_schema.test)
sql/sql_table.cc:
  Don't register errors from handler in drop table (as we already do it the upper level DROP TABLE code)
  Don't register errors for 'restore_table' as in most cases the table doesn't exists
sql/sql_union.cc:
  Use file->write_row() instead of 'write_record'.
  This gives us easer to handle error messages and is faster than the old version

sql/sql_class.cc

@@ -204,7 +204,7 @@ THD::THD()
 #endif
   net.last_error[0]=0;				// If error on boot
   ull=0;
-  system_thread= cleanup_done= abort_on_warning= 0;
+  system_thread= cleanup_done= abort_on_warning= no_warnings_for_error= 0;
   peer_port= 0;					// For SHOW PROCESSLIST
 #ifdef	__WIN__
   real_id = 0;