Support for BrandWeg as a class library

BrandWeg is a port of OpenJDK code to the Classpath interface, using it will allow us to plug holes in our class library like the missing java.util.Scanner. Here is Andrew Hughes' announcement from the Classpath mailing list:

Hi everyone,

We've just moved BrandWeg so that it is now housed alongside IcedTea
and IcePick on the Mercurial server. You can obtain a copy using:

hg clone http://icedtea.classpath.org/hg/brandweg

A reminder or for those who don't yet know: The BrandWeg project is a
fusion point for two Free Software projects: GNU Classpath and
OpenJDK. It mirrors the existing IcedTea project in providing a hybrid
of the two. However, whereas IcedTea approaches this from the
perspective of building and patching OpenJDK, we instead take GNU
Classpath as the baseline and bring in elements of the OpenJDK to fill
the remaining holes.

Patches welcomed
– Andrew