[CMake] find_package vs. include

[Robert Haines]

Hi all,

As far as I can tell both (for example) find_package(MPI) and  
include(FindMPI) do the same thing. All the required bits and pieces  
are set and usable for the rest of the build.

Is there any difference under the hood, and should I be using one in  
preference to the other?

Thanks,
Rob