- no functional changes
- outdated descriptions were removed/updated
- reduced number of necessary iterations over the zone nodes

- 'dnssec-keydir' is set for all zones
- 'dnssec-enable' is set for all zones, can be overridden for individual zone

- connections are generated when NSEC3 nodes are created
- explicitly request node connecting when the zone is loaded or after incoming transfer

- always use OpenSSL EVP
- do not touch output parameters if there is an error
- do not abort when there is an allocation error
- prepare for additional hash algorithms
- remove debug outputs

refs #2413

Change-Id: I0b0a572eb5cc11787e332404226b0b079ed85f88

refs #2413

Change-Id: I3d97bc4ea2f0986900c503bd10bc5f5ceb2585a6

The public key is specified as DNS RR. Before this patch, only first
line of the input file was read even if it contained comment, white
spaces or just a part of the RR.

refs #2413

Change-Id: I4cf3374121fbb676d89a52fa4ba741e497b04564

refs #2413

Change-Id: I44e0e6b9058781d58c54ee8521e294836ee4e183

refs #2413

Change-Id: I071d0a4560ded8051352ee6d30513a8c10b51a02

Allows cleaning up of the digest context to create multiple signatures.

refs #2413

Change-Id: Idcc23b99269d266d2ed1cbb6abda0bc73ec07338

refs #2413

Change-Id: I8c40b8bdf39bff7cf4e5d6ae41cb2612b634b932

refs #111

* xfrin_add_new_node and ddns_add_new_node were duplicates
  - knot_node_set_zone() was called in the _add functions anyway
* merged checks for NSEC3-related RR to knot_rrset_is_nsec3rel()
  - the empty RR check was pointless, as even if empty, the node
    shouldn't be searched in normal tree

Refs #102

     - Inserting DNAMEs from out-of-zone RRs into tmp DNAME table messed
things up when we free'd the RRSet, it's better to check before
inserting into table (one could rollback the table, but there are some
corner cases not worth solving)

Refs #102