Include Copyright notices in clawpack solver extensions #967

Job	Run time
CMake build on MacOS	7m 3s
CMake Serial Minimal Build on Linux	1m 4s
CMake Serial With Clawpack Build on Linux	9m 37s
CMake Serial With Clawpack and HDF Build on Linux	10m 32s
CMake Serial With GeoClaw Build on Linux	3m 55s
CMake Serial With CudaClaw (CUDA 10.1) Build on Linux	2m 52s
CMake Serial With CudaClaw (CUDA 11.3) Build on Linux	3m 18s
CMake MPI Minimal Build on Linux	2m 14s
CMake MPI With Clawpack Build on Linux	8m 22s
CMake MPI With Clawpack and HDF Build on Linux	9m 41s
CMake MPI With GeoClaw Build on Linux	3m 48s
CMake MPI With CudaClaw (CUDA 10.1) Build on Linux	2m 47s
CMake MPI With CudaClaw (CUDA 11.3) Build on Linux	3m 49s
CMake MPI With ThunderEgg Build on Linux	3m 49s
	1h 12m 51s

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