Changes between 0.9.6 and 0.9.7 [xx XXX 2000]
+ *) Tolerate nonRepudiation as being valid for S/MIME signing and certSign
+ keyUsage if basicConstraints absent for a CA.
+ [Steve Henson]
+
*) Make SMIME_write_PKCS7() write mail header values with a format that
is more generally accepted (no spaces before the semicolon), since
some programs can't parse those values properly otherwise. Also make