This allows to easily change the type of elements in a vector
expression, which can be useful to force a specific type when combining
vectors with different element types. For example, a double-vector can
be cast to float to avoid expensive computations in double precision.

Distributed argMin and argMax are not implemented yet, all other
operations successfully pass all tests (which were unified with the
tests for Vector, VectorView and StaticVector).

Does not work yet for the distributed vector...

getConstView should be always used for const operations, because
explicit is better than implicit. Overloading one method for cases which
have a completely different type (ConstViewType is *not* just a
const-qualified ViewType) can be very unclear (or even ambiguous) in
certain cases.

Fixed ambiguity between vector operations for StaticVector, DistributedVector and DistributedVectorView