bump version to 2.0.0-beta

NEWS

-Knot DNS 1.99.1 (2015-02-11)
-============================
-
-Features:
----------
- - DNSSEC: basic KASP support (generate initial keys, ZSK rollover)
-
-Knot DNS 1.99.0 (2014-12-31)
-============================
+Knot DNS 2.0.0-beta (2015-04-23)
+================================
 
 Features:
 ---------
  - DNSSEC: separate library, switch to GnuTLS, new utilities
+ - DNSSEC: basic KASP support (generate initial keys, ZSK rollover)
+ - configuration: new text format in YAML, binary store in LMDB
 
 Knot DNS 1.6.3 (2015-04-08)
 ===========================

configure.ac

 #                                               -*- Autoconf -*-
 
 AC_PREREQ([2.60])
-AC_INIT([knot], [1.99.1], [knot-dns@labs.nic.cz])
+AC_INIT([knot], [2.0.0-beta], [knot-dns@labs.nic.cz])
 AM_INIT_AUTOMAKE([gnits subdir-objects dist-xz -Wall -Werror])
 AM_SILENT_RULES([yes])
 AC_CONFIG_SRCDIR([src/knot/main.c])