WHATSNEW: Add release notes for Samba 4.2.10.

WHATSNEW: Add release notes for Samba 4.2.10.

o  CVE-2015-5370 (Multiple errors in DCE-RPC code)
o  CVE-2016-2110 (Man in the middle attacks possible with NTLMSSP)
o  CVE-2016-2111 (NETLOGON Spoofing Vulnerability)
o  CVE-2016-2112 (LDAP client and server don't enforce integrity)
o  CVE-2016-2113 (Missing TLS certificate validation)
o  CVE-2016-2114 ("server signing = mandatory" not enforced)
o  CVE-2016-2115 (SMB IPC traffic is not integrity protected)
o  CVE-2016-2118 (SAMR and LSA man in the middle attacks possible)

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11744

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>