openssh: update to 7.3p1 and remove some patches

openssh: update to 7.3p1 and remove some patches

Removed patches:

0001-Include-priv.h-for-priv_set_t.patch
 - already in 7.3.
0005-Reorganise-man-pages-into-Illumos-numbering-adjust-t.patch
 - we don't want to do this for unleashed.
0006-Deprecated-SunSSH-options.patch
0009-Add-DisableBanner-option.patch
0012-SunSSH-compat-default-config-values.patch
0013-Deprecate-SunSSH-compatible-server-options.patch
0021-Compatibility-fix-for-ListenAddress.patch
 - SunSSH compatibility is not a goal.
0015-GSS-API-key-exchange-support.patch
 - Too intrusive to properly maintain.
0020-PubKeyPlugin-support.patch
 - AuthorizedKeysCommand provides similar functionality and is maintained
   upstream.
0022-Hack-around-umac_ctx-name-punning.patch
 - already in 7.3.
0023-Try-to-create-privsep-chroot-dir-if-it-doesn-t-exist.patch
 - useful for Joyent, but not necessary for us -- /var/empty is shipped by the
   package.
0027-Re-enable-DSA-keys-for-pk-auth.patch
0030-Compatibility-for-SunSSH_1.5-should-include-old-DH-K.patch
 - DSA pubkey auth and old dh kex algos are disabled by default in
   upstream openssh for a reason.
0029-Set-default-sshd-options-based-on-etc-default-login.patch
 - I think this feature has potential to be surprising. I don't like it.
0032-Temporarily-set-ssh-keygen-and-ssh-add-to-old-FP-for.patch
 - Joyent specific hack that we don't want.
0033-Restore-tcpwrappers-libwrap-support.patch
 - I don't even know why this patch was implemented.