* ext/openssl/extconf.rb: add check for assert.h.

* ext/openssl/ossl.c (ossl_buf2str): new function to convert
  C buffer to String and free buffer.

* ext/openssl/ossl.c (ossl_x509_ary2sk): new function to convert
  Array of OpenSSL::X509 to STACK_OF(X509) with exception safe.

* ext/openssl/ossl.c (ossl_to_der, ossl_to_der_if_possible): new
  functions to convert object to DER string.

* ext/openssl/ossl.h: ditto.

* ext/openssl/ossl_bio.c (ossl_membio2str): new function to convert
  BIO to String object and free BIO.

* ext/openssl/ossl_bio.h: ditto.

* ext/openssl/ossl_pkcs7.c (ossl_pkcs7_to_der): add for "to_der".

* ext/openssl/ossl_x509name.c (ossl_x509name_to_der): ditto.

* ext/openssl/ossl_x509ext.c (ossl_x509ext_to_der): ditto.

* ext/openssl/ossl_x509ext.c (create_ext_from_array): removed
  and reimplement in openssl/x509.rb.

* ext/openssl/ossl_x509attr.c: reimplemented and disable some
  method temporarily. this class doesn't work fine without ASN.1
  data support;-) I'll rewrite in near future.

* ext/openssl/lib/openssl/x509.c (X509::Attribute): get rid off
  unused code.

* ext/openssl/lib/openssl/x509.c (X509::ExtensionFactory): refine all.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4558 b2dd03c8-39d4-4d8f-98ff-823fe69b080e