Fixes #100.
The file with the addresses is in the repo, so people don't have to
regenerate it, but the build system is able to do it.

The implementation is now similar to set-associative caches
that x86 CPU use.  Also the API is changed a bit, leading to
slight simplification of our use patterns.

Marek Vavrusa authored 8 years ago and Ondřej Surý committed 8 years ago

the cookies require libknot>=2.3, Makefile didn't
check for that, and turning cookies off wasn't
possible either

Karel Slaný authored 8 years ago and Ondřej Surý committed 8 years ago

Use ENABLE_cookies=yes variable to compile functionality.

this change introduces new API for cache backends,
that is a subset of knot_db_api_t from libknot
with several cache-specific operations

major changes are:
* merged 'cachectl' module into 'cache' as it is
  99% default-on and it simplifies things
* not transaction oriented, transactions may be
  reused and cached for higher performance
* scatter/gather API, this is important for
  latency and performance of non-local backends
  like Redis
* faster and reliable cache clearing
* cache-specific operations (prefix scan, ...) in
  the API not hacked in
* simpler code for both backends and caller

by default, build system attempts to use LMDB
from the system. however if it's not found or
the version is too old, it uses the built-in
snapshot in contrib

this is not going to be backwards compatible change, but it will be the first tagged libknot release sufficient for resolver

thanks @darix!
fixes #21,#22

* PIE,RELRO+NOW and other security features enabled
* support for both static/dynamic builds with BUILDMODE
* dynamic library is ABI-versioned, starting at 1
* pkg-config file is installed

this is needed to make sure it always compiles with PIC

RRSets are merged by using stash_add().