OpenVPN v2.4.2 release

2017.05.11 -- Version 2.4.2
David Sommerseth (5):
      auth-token: Ensure tokens are always wiped on de-auth
      docs: Fixed man-page warnings discoverd by rpmlint
      Make --cipher/--auth none more explicit on the risks
      plugin: Fix documentation typo for type_mask
      plugin: Export secure_memzero() to plug-ins

Hristo Venev (1):
      Fix extract_x509_field_ssl for external objects, v2

Selva Nair (1):
      In auth-pam plugin clear the password after use

Steffan Karger (10):
      cleanup: merge packet_id_alloc_outgoing() into packet_id_write()
      Don't run packet_id unit tests for --disable-crypto builds
      Fix Changes.rst layout
      Fix memory leak in x509_verify_cert_ku()
      mbedtls: correctly check return value in pkcs11_certificate_dn()
      Restore pre-NCP frame parameters for new sessions
      Always clear username/password from memory on error
      Document tls-crypt security considerations in man page
      Don't assert out on receiving too-large control packets (CVE-2017-7478)
      Drop packets instead of assert out if packet id rolls over (CVE-2017-7479)

ValdikSS (1):
      Set a low interface metric for tap adapter when block-outside-dns is in use