Fix markup to be compatible with Sphinx and add rough API doc
diff --git a/OpenSSL/crypto/crl.c b/OpenSSL/crypto/crl.c
index 97326f8..6a14bce 100644
--- a/OpenSSL/crypto/crl.c
+++ b/OpenSSL/crypto/crl.c
@@ -85,7 +85,7 @@
 Add a revoked (by value not reference) to the CRL structure\n\
 \n\
 :param cert: The new revoked.\n\
-:type cert: L{X509}\n\
+:type cert: :class:`X509`\n\
 :return: None\n\
 ";
 static PyObject *
@@ -113,13 +113,13 @@
 export(cert, key[, type[, days]]) -> export a CRL as a string\n\
 \n\
 :param cert: Used to sign CRL.\n\
-:type cert: L{X509}\n\
+:type cert: :class:`X509`\n\
 :param key: Used to sign CRL.\n\
-:type key: L{PKey}\n\
-:param type: The export format, either L{FILETYPE_PEM}, L{FILETYPE_ASN1}, or L{FILETYPE_TEXT}.\n\
+:type key: :class:`PKey`\n\
+:param type: The export format, either :py:data:`FILETYPE_PEM`, :py:data:`FILETYPE_ASN1`, or :py:data:`FILETYPE_TEXT`.\n\
 :param days: The number of days until the next update of this CRL.\n\
-:type days: L{int}\n\
-:return: L{str}\n\
+:type days: :py:data:`int`\n\
+:return: :py:data:`str`\n\
 ";
 static PyObject *
 crypto_CRL_export(crypto_CRLObj *self, PyObject *args, PyObject *keywds) {