File cleanup.

File cleanup.

svn:ignores cleanup.

Cleanup GNU TLS support.

Automatically generate a self-signed certificate and private key
as needed when using GNU TLS.

Add DefaultEncryption option so that we can require encryption by
default for authenticated access.

Map 401 unauthorized to 426 upgrade required when encryption is
required.

More documentation updates and reorg.

cups/http.c:
    - http_setup_ssl(): Add cast to gnutls_transport_set_ptr()
      call.

scheduler/auth.c:
    - cupsdIsAuthorized(): Fix inline comment (::1, not :::1).

scheduler/auth.h:
    - Add DefaultEncryption variable.

scheduler/client.c:
    - cupsdEncryptClient(): When setting up a GNU TLS session,
      check whether the key and certificate are present, and
      create them if not. Also add cast to
      gnutls_transport_set_ptr() call.
    - cupsdSendError(): Map HTTP_UNAUTHORIZED to
      HTTP_UPGRADE_REQUIRED if we need to encrypt the connection
      before authenticating.
    - cupsdWriteClient(): Use cupsdSendError() for Status:
      headers, only send transfer-encoding header for successful
      CGI calls, and don't return early otherwise cupsd will spin
      on the socket FD.
    - make_certificate(): Added for GNU TLS configurations.

scheduler/conf.c:
    - cupsdReadConfiguration(): Initialize DefaultEncryption to
      Required.
    - read_configuration(): Add support for DefaultEncryption
      directive.

git-svn-id: svn+ssh://src.apple.com/svn/cups/cups.org/trunk@5222 7a7537e8-13f0-0310-91df-b6672ffda945