BUG#25688 (RBR: circular replication may cause STMT_END_F flags to be

skipped):

By moving statement end actions from Rows_log_event::do_apply_event() to
Rows_log_event::do_update_pos() they will always be executed, even if
Rows_log_event::do_apply_event() is skipped because the event originated
at the same server. This because Rows_log_event::do_update_pos() is always
executed (unless Rows_log_event::do_apply_event() failed with an error,
in which case the slave stops with an error anyway). 

Adding test case.

Fixing logic to detect if inside a group. If a rotate event occured
when an initial prefix of events for a statement, but for which the
table did contain a key, last_event_start_time is set to zero, causing
rotate to end the group but without unlocking any tables. This left a
lock hanging around, which subsequently triggered an assertion when a
second attempt was made to lock the same sequence of tables.

In order to solve the above problem, a new flag was added to the relay
log info structure that is used to indicate that the replication thread
is currently executing a statement. Using this flag, the replication
thread is in a group if it is either in a statement or inside a trans-
action.

The patch also eliminates some gratuitous header file inclusions that
were not needed (and caused compile errors) and replaced them with
forward definitions.

sql/log_event.h

@@ -841,6 +841,7 @@ public:
   }
 
 protected:
+
   /**
     Primitive to apply an event to the database.
 
@@ -2242,6 +2243,7 @@ private:
 
 #if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
   virtual int do_apply_event(RELAY_LOG_INFO const *rli);
+  virtual int do_update_pos(RELAY_LOG_INFO *rli);
 
   /*
     Primitive to prepare for a sequence of row executions.