Linux package improvements

- Place python bindings in the correct place in the package.
- Automatically copy dependencies.
- Set binaries runtime paths (CMAKE_SKIP_RPATH must be off when building for runtime paths to work).
- Copy appleseed headers to package.

I think we need to refine some of the patterns, in particular meta and benchmark. As is, some header files such as `benchmarkresult.h` will be ignored.