Added Knot DNS server with utilities version 1.5.0-rc2.

Signed-off-by: Daniel Salzman <daniel.salzman@nic.cz>
Added User-space RCU library version 0.7.12.

Signed-off-by: Daniel Salzman <daniel.salzman@nic.cz>
Merge pull request #38 from salzmdan/master

Added Knot DNS server with utilities version 1.5.0-rc2.