Implemented support for START SLAVE UNTIL (WL#868)

include/mysqld_error.h:
  Added error codes for warnings and error messages for START SLAVE UNTIL
mysql-test/r/rpl000015.result:
  Fixed test because 3 new columns to SHOW SLAVE STATUS output were added
mysql-test/r/rpl_empty_master_crash.result:
  Fixed test because 3 new columns to SHOW SLAVE STATUS output were added
mysql-test/r/rpl_flush_log_loop.result:
  Fixed test because 3 new columns to SHOW SLAVE STATUS output were added
mysql-test/r/rpl_log.result:
  Fixed test because 3 new columns to SHOW SLAVE STATUS output were added
mysql-test/r/rpl_log_pos.result:
  Fixed test because 3 new columns to SHOW SLAVE STATUS output were added
mysql-test/r/rpl_redirect.result:
  Fixed test because 3 new columns to SHOW SLAVE STATUS output were added
mysql-test/r/rpl_replicate_do.result:
  Fixed test because 3 new columns to SHOW SLAVE STATUS output were added
mysql-test/r/rpl_rotate_logs.result:
  Fixed test because 3 new columns to SHOW SLAVE STATUS output were added
sql/lex.h:
  Added UNTIL symbol
sql/log.cc:
  Invalidating until_log_name comparison result if group_relay_log_name is changed
sql/log_event.cc:
  Invalidating until_log_name comparison result if group_master_log_name is changed
sql/repl_failsafe.cc:
  Cancel until condition if LOAD MASTER DATA is executed
sql/share/czech/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/danish/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/dutch/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/english/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/estonian/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/french/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/german/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/greek/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/hungarian/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/italian/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/japanese/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/korean/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/norwegian-ny/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/norwegian/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/polish/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/portuguese/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/romanian/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/russian/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/serbian/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/slovak/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/spanish/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/swedish/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/share/ukrainian/errmsg.txt:
  Added error and warning message for START SLAVE UNTIL
sql/slave.cc:
  Fixed wrong locking order in init_relay_log_pos()
  Added until condition fields to SHOW SLAVE STATUS
  Added checking if UNTIL condition is reached 
  (added proper method, added its invocation, reorganized locking 
  in exec_relay_log_event() and next_event())
sql/slave.h:
  Members in RELAY_LOG_INFO for storing UNTIL condition. Also 
  methods for for invalidation of cached UNTIL condition comparison
  results
sql/sql_repl.cc:
  Now honoring UNTIL clause then starting slave thread. Proper 
  errors and warnings.
sql/sql_yacc.yy:
  Added support for UNTIL clause in START SLAVE. This involved 
  extraction of some of master_defs to separate master_file_def
  non-terminal.

include/mysqld_error.h

@@ -288,4 +288,7 @@
 #define ER_CANT_AGGREGATE_NCOLLATIONS 1269
 #define ER_VARIABLE_IS_NOT_STRUCT 1270
 #define ER_UNKNOWN_COLLATION 1271
-#define ER_ERROR_MESSAGES 272
+#define ER_BAD_SLAVE_UNTIL_COND 1272
+#define ER_MISSING_SKIP_SLAVE 1273
+#define ER_UNTIL_COND_IGNORED 1274
+#define ER_ERROR_MESSAGES 275