[Dune] Boundary conditions, segments and indexing

[Carsten Gräser]

Hi Max,

Am 31.08.20 um 16:05 schrieb Firmbach, Max:
> I'm still on Dune 2.6 so I just took the changes from your merge request and
> 
> added them manually into my gmshreader.hh.
> 
> 
> At least from my side it seems to look fine, regarding the insertionindex.
as far as I can see your tags should then be OK, too.
Thanks for confirming the fix.

Best,
Carsten