pdns: Kill all spawned processes

Pipe backend spawned processes can still be alive after the pdns_server-instance was killed.
If the children remain alive, sockets will not be released, and the pdns_server-instance can't be respawned.

To be sure that all the spawned processes are killed, we must kill by using the process GID.
To be able to do the soft reloads, pdns_server-instance is declared as process group lider.

Also, all forced kills must kill by GID, not by PID, so all the processes would properly die.

Signed-off-by: Igor Maravic <igor@spotify.com>
Signed-off-by: Alexey Lapitsky <alexey@spotify.com>
Clean up after DynListener crash

When DynListener crashes, kill all processes from his parent PGRP.

This way we'll certanly close the pdns.controlsocket (no more hanging pdns_control processes)
and we'll kill the processes that aren't managable via pdns_control any more.
Add timeout to pdns_control connect, send and recv calls

If any of the connect, send and recv calls are timedout, TimeoutException is thrown.
main loop catches that exception and returns code 2.
code 1 is returned for all other exceptions.

In init.d script we now have 3 states:
UP
DOWN
UNRESPONSIVE

If the pdns_server is unresponsive, it will be killed.
After that, script continues as usual.
Clean up after the pdns_server-instance

Make sure that all children are killed after the pdns_server-instance dies
PDNS should always be the leader of the process group

That way, we can properly kill all of it's subprocesses!
Merge branch 'master' of https://github.com/i-maravic/pdns into i-maravic-master
disable dnssec-only tools during non-dnssec tests
only add ksk DNSKEY records to trustedkeys
remove deactive zsk in tests / remove unused bind-dnssec-setup file
remove unreferenced files from source tree
for FILE in $(git ls-files pdns/*); do
    git grep $(basename "$FILE") > /dev/null || echo "would remove $FILE"
done
Merge pull request #1108 from mind04/no-dnssec-tests

disable dnssec-only tools during non-dnssec test runs
Merge pull request #1109 from mind04/not-referenced

remove unreferenced files from source tree
Load AXFR-SOURCE when provided for domains
Fixed few nits
Enclosed lua check with set +e
Fixed indentation
Remove +e/-e
Whitespace fix
fix bindparser h/hh hack, thanks @stbuehler
Merge pull request #1086 from cmouse/use-axfr-source-freshness

Load AXFR-SOURCE when provided for domains