- Some usages still remain, they would require more systematic
  changes.

refs #1056 @2h

closes #1059 @10m

refs #1058 @15m

- Modified dname-table API a bit.
- Just switching old node pointer to new node pointer.
- Should not generate any problems.

closes #1058 @30m

refs #1046 @10m

- Setting the ptr in zone_add_node() function.
TODO: will have to be done other way when zone-contents instead
      of zone is used.

refs #1046 @20m

refs #1038 @15m, #1039 @15m

TODO: change the use of the API.
Note: Will not compile now

refs #1038 @20m @1039 @20m

- marking old node as old

- Separate functions for adding normal RRSets and RRSIG RRSets.
- Small fixes.

TODO: Ensure that all data are properly deallocated when the update
      fails!!

refs #1042 @45m

- Separated handling of RRSIGs from handling of normal RRSets.
- If RRSIGs are removed from RRSet, and the RRSet is already
  clear, the RRSet is removed as well.

refs #1041 @1h

refs #1035 @10m

- When a node copy is created, the old node is inserted into the
  list of old nodes so that it may be removed after update.
- Fixed node checking after update - empty new copies are deleted
  right away and removed from the old node.
- When finalizing, only old nodes not having new copy are removed
  from the zone structures.

refs #1035 @20m

- The zone is traversed, empty nodes are stored in the list of
  old nodes and their parents' children counts are decreased.
- This allows to remove parent-child chains.
- Removing of nodes is done in separate step because it modifies
  the structures used to iterate through the zone.
- Nodes are removed both from hash table and from the zone tree,
  but not deleted.

refs #1035 @20m

refs #1035 @15m

refs #1035 @15m

- Each time a parent is set, the parent's children count is
  increased.
- It is necessary that there is no manipulation with node and
  its children that does not use the API.

refs #1035 @10m

- References to old nodes replaced by references to new ones.
- Added API for this to node.
- Implemented reference fixing in XFR.

refs #1037 @20m

- Getting zone trees from zone contents.
- Applying functions to zone tree - zone tree functions require
  function working with zone tree node, i.e. the 'conversion'
  is done one layer above - in the zone contents.

refs #1037 @30m

closes #1040 @15m

- Copying node and copying RRSet separated to new functions.
- Removing empty RRSet from node.
- Various fixes of API usage.

refs #1034 @20m, #936 @2h

- node_new() sets flags to node.
- fixed node_set_previous() - properly connects the node to
  the chain of nodes.
- Modified calls to node_new() in all parts of the program.
- zone_contents_add_node() sets flags to created parents,
  checks if created nodes are not wildcard children,
  properly sets the last node's parent.
- Fixed zone_contents_add_nsec3_node() (parent setting).
- zone_contents_get_previous() + find/get_previous_nsec3() added.

- Adding new node during IXFR zone update implemented.

refs #1034 @2h

TODO: adding new node to the zone contents.

refs #936 @40m

refs #936 @3h

refs #1028

- Invalid reads and writes when checking references to already
  deleted nodes.
- Added macro for post-order reverse traversal to the AVL tree.
- Added function for post-order reverse traversal to zone-tree.
- References checking in node_free() are now done according to new
  parameter.
- Fixed usages of node_free()

refs #1028 @50m

- Added zone-contents module, most of zone functions moved there
  and adequately modified.
- Zone API functions just call the zone-contents functions now.
  Later should be removed totally.

- Few fixes.

refs #1028 @2h