Rotate event is automatically generated and written when rotating binary
log or relay log. Rotate events for relay logs are usually ignored by slave
SQL thread becuase they have the same server id as that of the slave.
However, if --replicate-same-server-id is enabled, rotate event
for relay log would be treated as if it's a rotate event from master, and
would be executed by slave to update the rli->group_master_log_name and
rli->group_master_log_pos to a wrong value and cause the MASTER_POS_WAIT
function to fail and return NULL.

This patch fixed this problem by setting a flag bit (LOG_EVENT_RELAY_LOG_F)
in the event to tell the SQL thread to ignore these Rotate events generated
for relay logs.

This patch also added another binlog event flag bit (LOG_EVENT_ARTIFICIAL_F)
to distinquish faked events, the method used before this was by checking if
log_pos was zero.

Memoize functions that converts between different paths, a given input string will always return the same output. This save a lot of calls to cygpath for example

- Updated slow_query_log_file_basic and general_log_file basis instead of the func version as
the func version run good but the basic versions fail.
- Sent innodb.test to dev@innodb.com.
- variables.test has differences probably due to a bug in mtr or in the SET statement (see bug#39369).
- general_log_file_basic.test and slow_query_log_file_bsaic.test have differences, which might be 
produced by the new mtr (see bug#38124).

Problem: <=> operator may return wrong results 
comparing NULL and a DATE/DATETIME/TIME value.

Fix: properly check NULLs.

statement/stored procedure

View privileges are properly checked after the fix for bug no 
36086, so the method TABLE_LIST::get_db_name() must be used 
instead of field TABLE_LIST::db, as this only works for tables.
Bug appears when accessing views in prepared statements.

SUPER is not required to change binlog format for session

A user without SUPER privileges can change the value of the
session variable BINLOG_FORMAT, causing problems for a DBA.

This changeset requires a user to have SUPER privileges to
change the value of the session variable BINLOG_FORMAT, and
not only the global variable BINLOG_FORMAT.