ports/159690: math/eigen2 fails with CMake

[Raphael Kubo da Costa]

linimon at FreeBSD.org writes:

> Synopsis: math/eigen2 fails with CMake
>
> Responsible-Changed-From-To: freebsd-amd64->kde
> Responsible-Changed-By: linimon
> Responsible-Changed-When: Fri Aug 12 11:00:27 UTC 2011
> Responsible-Changed-Why:
> Make this a ports PR and assign.
>
> http://www.freebsd.org/cgi/query-pr.cgi?pr=159690

It looks like BitBucket has changed their tarball naming scheme and the
top-level folder in the tar.bz2 file is now called eigen-eigen-2.0.16
instead of eigen-eigen-9ca09dbd70ce.

Changing WRKSRC in the Makefile should fix the issue (can't do that now
because the internet connection is really bad in the place I'm currently
in).