PG-PuReMD: utlize multiple CUDA streams to run independent kernels in the ReaxFF+QEq task dependency graph.

PG-PuReMD: fix stream issue with cudaMemset's happening in default stream (switch to cudaMemsetAsync). Rework memory management in light of this change.

WIP: finish the explicit single stream port by using cudaMemcpyAsync and cudaStreamSynchronize calls.

WIP: changes to support multiple CUDA streams. This commit contains porting of all kernels from the default stream to a single non-default stream. This commit has bugs regarding cudaMemcpy's still being in the default stream (and synchronous).

PG-PuReMD: implement MPI+CUDA versions of SDM, PIPECG, PIPECR for charge solver methods (along with missing dual QEq versions).

PG-PuReMD: use a warp of threads for addtional bonded interaction computations (bond orders, bonds, lone pair/over/under).

PG-PuReMD: use a warp of threads for apply bond derivatives to forces and simplify these code paths.

PG-PuReMD: fix incorrect summations in kinetic energy and temperature calculation functions. Replace several hand-coded device-wide reduction kernels with CUB libary reduction.

PG-PuReMD: split bond and hbond initialization kernels for future optimizations. Cleanup CUDA code related to far neighbor list being in full format (remove unnecessary conditionals and arithmetic).

sPuReMD: enable setting the number of OpenMP threads via control file keyword or OpenMP environment variable (OMP_NUM_THREADS).

sPuReMD: make zlib dependency optional (trajectory file compression). PG-PuReMD: remove erroneous zlib header file inclusion.

sPuReMD: fix OpenMP compilation issue with specifications prior to 4.0 (behavior change regarding implicit shared attribute assignment to const variables).

QMMM interface related: ignore QM-MM bonds while forming bond lists, update charge matrix so that the total charge constraint only applies to QM atoms