Disable introspection during distcheck
Release 0.6.5
Fix Iterator.remove in PriorityQueue
Ommited change to fix build
Release 0.6.6
Release 0.6.6.1
PriorityQueue: fix segfault discovered during stress-testing

If node P is removed then set P to R, as described in paper, instead of
NULL.
Fix Gee.List.Iterator.next
Small improvements to PriorityQueue
Release 0.6.7
Fix memory leak in TreeSet and TreeMap
Release 0.6.8