sql/ha_innodb.cc:
  Removed variable innobase_auto_extend_increment
  (access srv_auto_extend_increment directly)
sql/ha_innodb.h:
  Removed variable innobase_auto_extend_increment
  (access srv_auto_extend_increment directly)
sql/mysqld.cc:
  Moved innodb_autoextend_increment to alphabetically correct position.
  Replaced innobase_auto_extend_increment with srv_auto_extend_increment.
sql/set_var.cc:
  Added innodb_autoextend_increment