[eigen] ViennaCL 1.1.1 with Eigen interface released

[Karl Rupp <rupp@xxxxxxxxxxxxxxxx>]

Dear Eigen users,

as posted on this list a few of weeks ago, the latest ViennaCL 1.1.1 
release now provides an out-of-the-box interface for Eigen. Small source 
examples are available here:
http://viennacl.sourceforge.net/viennacl-examples-eigen.html

The first snippet shows the initialization of ViennaCL objects with data 
from Eigen objects, the second snippet shows that the iterative solvers 
from ViennaCL can directly be used with sparse matrices from Eigen. By 
now, the preconditioners shipped with ViennaCL cannot be used directly 
with Eigen matrices, but a wrapper is scheduled for the next release.

As suggested by Benoit, feel free to grab some of the ViennaCL sources 
and include it in your library. Our MIT license should not pose any 
troubles. :-) Any other suggestions are always welcome.

Best regards,
Karli