[Dune] Removal of GenericGeometry::normal()

[Christoph Grüninger]

Hi Oliver,
you removed dune-geometry in revision 62. What is the intended 
replacement? I'd like to fix the broken make check for dune-grid due to 
this change.

Thanks
Christoph

-- 
People who are more than casually interested in computers should have
at least some idea of what the underlying hardware is like. Otherwise
the programs they write will be pretty weird.         -- Donald Knuth