PG-PuReMD: fix CUDA compilation error. Revert library building via libtool due to issues with recognizing custom suffix rules for building CUDA source files and revisit at a later date.

sPuReMD: make CoM logic consistent with PuReMD. Other build system updates for debugging and newer versions of MPICH.

PG-PuReMD: fix nvcc build issue where incorrect C++ compiler was utilized. Fix race condition with three body list computation. Remove debug code. Other misc. refactoring.