Change-Id: I8b934ca1f9cd0b80f7e1ede479674c269415f2da

Move (and sometimes add) #include <config.h> at the top of
all *.c files.

Remove all #include ["<]config.h[">] from headers files.

Change-Id: I1df07602d0240affd95e12fccd122558300d2145

Change-Id: Ib6cd9693be87c53f9f1be0f54ef05164f217f2c0

Change-Id: I39d236a0d6594692597f2e66624f0b0d56928c34

Change-Id: I7d4597e875a42805c307b2c1ed75ed309bf3b37a

- Simplified and decoupled I/O from processing code.
- Single reader with multiple workers.
- Reader is bound to specific CPU for lowest possible latency.
- Reverted to select() instead of fdset wrapper as epoll/kqueue could
  be quite slower for a single or handful of sockets.
- Reader I/O calls are non-blocking.

General idea is:
- Reader takes free request from a rx_queue
- Receives data and pushes it to the tx_queue
- Worker processes the packets, sends answers and returns the request
  to the rx_queue

Semi lock-free queue is used for communication.
This is measured to be slightly better than singlethreading, as socket
contention could be better predicted - the reader cannot check sockets
for new events when tx_queue is full.

Change-Id: Ifc40889b355404a9e78e10d77c26cb3fc4c58386

This reduces number of used threads for I/O to constant:
 CPU_COUNT * 3 instead of IF_COUNT * (CPU_COUNT * 3 + 1)

fixes #1772 @2.5h

Conflicts:

	src/knot/server/tcp-handler.c
	src/knot/server/xfr-handler.c
	src/knot/server/zones.c
	src/libknot/nameserver/name-server.c
	src/libknot/updates/xfr-in.c
	src/tests/libknot/libknot/response_tests.c

fixes #1772 @2.5h

fixes #1773 @1.5h

This prevents potential racing conditions and doesn't require locking,
as it's per worker.

refs #1608

Fixes #1104 @1h

Quick measures show 20-30% improvement over recvfrom().

Commit refs #603.

 KNOT -> KNOTD
 DNSLIB -> KNOT

refs #1087 @20m

Lots of warnings, redefinitions.
TCP is not working (disabled).

Commit refs #831.

XFR handler uses event queue for receiving requests.
Each XFR handler thread asynchronously listens for events like UDP handler.

Commit refs #752.

- Macro for conditional compilation of hash table was not visible
  in dnslib. Moved to dnslib-common.h

This includes:
- base32 encoding
- dynamic array
- skip-list
- latency profiling
- print routines
- Bird list
- Slab allocator
- AVL tree

refs #400

- Sources separated according to the future compilation modules:
  - src/knot/ contains all sources related to server (compiles into
    knotc and knotd)
  - src/alloc/ contains sources of slab allocator (may be compiled
    into standalone library).
  - src/dnslib/ contains dnslib sources (may be compiled as
    standalone library).
  - src/tests/ contains unittests (compiles into unittests).
  - src/zoneparser/ contains sources of zone compiler (compiles
    into knot-zcompile).

TODO: Need to refactor makefile to separate the compilation of
      these modules. However, unittests still depend on all
      modules.

refs #400

- Chopping labels from domain name instead of using parent

Note: Leads to significant slowdown, so conditional compilation
      utilized.

TODO: try to use this approach only if the parent is unusable, may
      speed it up

- The structure (us_system_t) keeps the coeficients of the
  system of functions.
- It is used in cuckoo hash table - one system per table.

fixes #621

- Added function zone_find_previous().
- Added searching for previous node when asked for NSEC records
  in some nameserver functions.
- Searching in tree separated.
- Minor changes to nameserver NSEC/NSEC3 functions (checking if
  NSEC3 is enabled)

refs #606