[xmlsec] New xmlsec 1.2.12 release

[Aleksey Sanin]

The new XML Security Library 1.2.12 release available at
the usual place:

    http://www.aleksey.com/xmlsec/download.html

It includes the following changes:

* Fixed HMAC vulnerability with small values of HMAC
   length (CERT VU #466161). For more details, see
   http://www.kb.cert.org/vuls/id/466161
* Added support for the GOST implemented by Russian Crypto
   Pro CSP.
* Added an option to return the replaced node.
* Added new function xmlSecNodeEncodeAndSetContent for
   encoding special chars in the node content.
* Added configurable Base64 line length.
* Bug fixes.

Thanks to everyone for the contribution and bug reports!

Aleksey Sanin