Initialize underlying data in Point

Revert "Only add the link path for clang"

Improve error messages in BVH constructor and BVH::query()

Add intersects(Point, Box)

This reverts commit 1564b746.

The compiler identification breaks downstream gfortran builds. The pull
request #49 does not have any information why this modification was
suggested in the first place.

Update FindKokkos.cmake

- Make sure that we fail if Kokkos' PkgConfig module was not found
- Propagate Kokkos compilation flags only for C++

Access traits for predicates