[ethmac] Webpage and eth. spec. updated

["Igor Mohor" <igor.mohor@uni-mb.si>]

Hi, everybody,

I updated the MIIM part of the ethernet core spec. 
O also uploaded (to cvs) the MIIM module and a testbench.
Everything can be found at http://www.opencores.org/cores/ethmac/.

As always comments are welcome but don't go crazy :)

Regards, 
            Igor