refactor queue spool directory config handling
queue: spool directory setting was not properly propagated to DA queue
doc: maintain ChangeLog
Merge branch 'v7-stable' into v7-devel

Conflicts:
	runtime/queue.c
queue: add config parameter queue.spooldirectory

Conflicts:

	runtime/queue.c
doc: add new queue parameter
Merge branch 'v7-devel'