Hook up PKCS#11 PIN entry through configured passphrase entry method.

* modules/ssl/ssl_engine_pphrase.c: Add wrappers for OpenSSL UI * API
  around passphrase entry.
  (modssl_load_engine_keypair): Take vhost ID and use above rather than
  default OpenSSL UI.

* modules/ssl/ssl_engine_init.c (ssl_init_server_certs): Pass vhost ID.

Submitted by: Anderson Sasaki<ansaski redhat.com>, jorton


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1835240 13f79535-47bb-0310-9956-ffa450edef68