Portability fixes and cleanups
Fixed setting of 'res' in mysql_execute_command()


sql/handler.cc:
  delete_table() will not return error for not found files if one handler file was found and deleted
sql/handler.h:
  Incremented MAX_HA so that ndb works again
  Don't convert char pointer to (my_xid*) as we don't know if the address is aligned on 8
sql/log.cc:
  Indentation fixes
  Simplified loop to find next log
  Fixed race condition in reset_logs that caused mix_innodb_myisam_binlog to fail
sql/log_event.cc:
  Don't convert char pointer to (my_xid*) as we don't know if the address is aligned on 8
sql/sql_acl.cc:
  Convert db name directly to avoid extra strmov
sql/sql_base.cc:
  Added comment
  Removed not needed code
sql/sql_db.cc:
  Added comment
  Remove not needed code
sql/sql_parse.cc:
  Always call mysql_rm_db() with lower case db name
  Ensure that 'res' is set correctly in mysql_execute_command()
  (One don't have to set res if one calls my_error() and res should be = 0 for correct commands)
sql/sql_repl.cc:
  Indentation fixes
  use packet->ptr() instead of packet->c_ptr()
sql/sql_table.cc:
  Join similar code when table didn't exist in engine