Release 1.3.1

[drcf...@gmail.com]

With the recent changes updating to a fresher Mono.Cecil, and more
friendly handling of signed assemblies (now displays an error rather
than invalidating the signature), I've posted
a new binary release.

Come and get Obfuscar 1.3.1: http://code.google.com/p/obfuscar/downloads/detail?name=Obfuscar_1.3.1.tar.gz

For more details, see the svn log.