Add missing include

See also bug #1.

See merge request !1

it now exploits the fact, that refinement calls are boolean
due to the recursive nature neighbours may be assigned at the wrong time
which in parallel leads to wrong face refinements.
this is caught by returning false and the refinement is
initiated again.

We decided to host the dune-alugrid repository on the HD gitlab server in the
future. This server will reject pushes containing trailing white space.
Therefore we also enable the white-space hook for dune-alugrid, so that we are
already notified about this problem at commit time.

[bugfix] the recursive algorithim for bisection requires setting the refinement request to nosplit at the end of the method

5ea9cba1.

There is no mpAccess().gmax( unsigned int ) which is used within an assert.

compatiblity.