commit data structures for adjustment methods

Signed-off-by: Mattias Andrée <maandree@operamail.com>
add functions that should be used by the common code to free method specific data

Signed-off-by: Mattias Andrée <maandree@operamail.com>
add functions for freeing resources

Signed-off-by: Mattias Andrée <maandree@operamail.com>