Security update for cyrus-imapd (important)

This update for cyrus-imapd fixes the following issues:

• Previous versions of cyrus-imapd would not allow its users to disable
  old SSL variants that are vulnerable to attacks like BEAST and POODLE.
  This patch adds the configuration option ‘tls_versions’ to remedy that
  issue. Note that users who upgrade an existing installation will not
  have their imapd.conf file overwritten, i.e. their IMAP server will
  continue to support SSLv2 and SSLv3 like before. To disable support for
  those protocols, edit imapd.conf manually to include "tls_versions:
  tls1_0 tls1_1 tls1_2". New installations, however, will have an
  imapd.conf file that contains these settings already, i.e. newly
  installed IMAP servers do not support unsafe versions of SSL unless
  that support is explicitly enabled by the user. (bsc#901748)

• An integer overflow vulnerability in cyrus-imapd’s urlfetch range
  checking code was fixed. (CVE-2015-8076, CVE-2015-8077, CVE-2015-8078,
  bsc#981670, bsc#954200, bsc#954201)

• Support for Elliptic Curve Diffie–Hellman (ECDH) has been added to
  cyrus-imapd. (bsc#860611)