Unit tests for the old alugrid fail to compile

With g++-4.9.2, autotools buildsystem, alugrid-1.52 (tar ball), and today's releases/2.4 branches (dune-common@532a9f30, dune-geometry@1d263376, and 32b29ad3), ALUGrid-related unit tests fail to compile. The issues encountered seem to be mostly related to EntityPointer -> Entity conversions.

See also !30 (merged).