Dennis Gläser authored Oct 22, 2016 and Timo Koch committed Nov 23, 2016

Up to now the types for the inner and boundary interaction volume seeds
were always identical. For the mpfa-l and other methods, it would be more efficient
if these types could differ, as e.g. the sizes of the containers are known at compile time
for the l method. This commit introduces the capability of the types to differ.