This reverts commit 3930c9f46623f4f0c92f240bdde001920514b6a0.

Obviously, Dune::FloatCmp compares scalars, and not vectors.

This reverts commit 6c60dedac35f1e833f9f38e820f82db314566123.
According to @renemilk, this is not needed:

Call Dune::FloatCmp::ne instead?
Also: failure += condition_expression()

is probably obsolete, this should be in common somewhere

configcontainer.hh:39:13: note: copy assignment operator of 'Request' is implicitly deleted because field 'line' is of const-qualified type 'const int'
  const int line;
            ^

http://stackoverflow.com/a/8165154

This reverts commit c7040907008337517833c460dad4474f8b727c2f.