Fix most of the doc compilation warning/errors

There's still a "<autodoc>:: (ERROR/3) Unknown target name: "ssleay"." error though :(
diff --git a/OpenSSL/crypto/x509.c b/OpenSSL/crypto/x509.c
index ab8348f..4329ddb 100644
--- a/OpenSSL/crypto/x509.c
+++ b/OpenSSL/crypto/x509.c
@@ -254,7 +254,7 @@
 Set the subject of the certificate\n\
 \n\
 :param subject: The subject name\n\
-:type subject: :FOOBAR:`X509Name`\n\
+:type subject: :py:class:`X509Name`\n\
 :return: None\n\
 ";
 
@@ -433,12 +433,13 @@
 static char crypto_X509_get_notBefore_doc[] = "\n\
 Retrieve the time stamp for when the certificate starts being valid\n\
 \n\
-:return: A string giving the timestamp, in the format:\n\
+:return: A string giving the timestamp, in the format::\n\
 \n\
                  YYYYMMDDhhmmssZ\n\
                  YYYYMMDDhhmmss+hhmm\n\
                  YYYYMMDDhhmmss-hhmm\n\
-           or None if there is no value set.\n\
+\n\
+         or None if there is no value set.\n\
 ";
 
 static PyObject*
@@ -455,12 +456,13 @@
 static char crypto_X509_get_notAfter_doc[] = "\n\
 Retrieve the time stamp for when the certificate stops being valid\n\
 \n\
-:return: A string giving the timestamp, in the format:\n\
+:return: A string giving the timestamp, in the format::\n\
 \n\
                  YYYYMMDDhhmmssZ\n\
                  YYYYMMDDhhmmss+hhmm\n\
                  YYYYMMDDhhmmss-hhmm\n\
-           or None if there is no value set.\n\
+\n\
+         or None if there is no value set.\n\
 ";
 
 static PyObject*