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

PG-PuReMD: change CUDA kernel error checking to only make calls to cudaDeviceSynchronize when in debugging mode (non-debug builds thus have better performance with kernel asynchronous launch behavior in single default stream). Change file I/O to only flush when in debugging mode (non-debug builds allow the I/O operations to be grouped for better performance).

PG-PuReMD: fix performance logging code around GPU code. Rearrange header files to allow some preprocessor definitions to be defined via options in configure script. Rework Autoconf and Automake code to allow passing flags directly to nvcc compiler wrapper (for CUDA code). Enable C11 and C++11 standard targets during compilation.

PG-PuReMD: corrections for utilizing a SAI preconditioner in MPI code (errors introduced during previous code merges).

PG-PuReMD: revert CG solver convergance criterion to used preconditioned residual norm. Re-enable dual charge solver for QEq.

PG-PuReMD: rework performance logging code in linear solver routines to avoid excessive MPI communications.

PG-PuReMD: adjust performance logging to compute mean timings across all processors. Other code clean-up.

PG-PuReMD: fix issue with charge solver preconditioner refactoring rate causes issues with reneighboring actions (preconditionering rate was previously coupled with reneighoring rate for SAI but this causes issues for Jacobi, etc.). Be more greedy with memory allocation sizes to decrease reallocation frequency (MPI buffers, etc.). More GPU code clean-up.

PG-PuReMD: fix MPI buffer allocations sizes. Ensure that nonblocking MPI messages have completed for each dimension before continuing. Rework reallocation checks in integration routines. Temporarily disable CUDA-aware MPI code paths (need to perform packing/unpacking first on device before handing off pointers). Other code clean-up.

PG-PuReMD: fix host-device transfers for charge solver code (SpMV data transfer sizes). Remove unused code. Other general code clean-up.

PG-PuReMD: fix issue with divergent MPI_Reduce calls by multiple MPI processes (timing logging code). Add run-time MPI routine error checking. Fix issue with upper limit of hydrogen atoms allowed being hard-coded in GPU code (use dynamic memory allocation instead). Other code clean-up.

PG-PuReMD: clean-up MPI custom datatype initialization and error reporting. Avoid truncations in buffer size calculations. Other code clean-up.

PG-PuReMD: merge changes from sPuReMD and PuReMD for validation work for simulation accuracy. Small correction to lone pair energy calculation. PuReMD: code formatting changes to better align with sPuReMD. sPuReMD: fix issue with valence angle calculations not setting list indices under certain sitations (taking previous continue statement missed index assignment).

PG-PuReMD: fix issue with portions of interaction lists not being initialized for Cuda_Init_Forces. Utilize more targeted debugging prints (DEBUG -> DEBUG_FOCUS). Other general code cleanup.

PG-PuReMD: update build system for LAPACKE. Conditionally include LAPACKE header based on results of compilation.

PG-PuReMD: fix initial list offsets for creating lists. Fix far neighbor and hydrogen bond reallocation checks. Begin refactoring function defitions and declarations to allow compiler to enforce intentions of pointer usage.

PG-PuReMD: fix charge extrapolation. Improve memory management of local portion of charge matrix and reset linear system size for each time step.

PG-PuReMD: fix issue with MPI outgoinging buffer size. Refactor MPI communication code for better encapsulation. Continue cleaning up linear solver code.

PG-PuReMD: begin merging preconditioner code from sPuReMD. Make data structures between sPuReMD and PG-PuReMD consistent. Update control file parsing.

PG-PuReMD: merge memory management and step retry logic from MPI+GPU code into MPI-only code. Fix and backport numerous bugs (void pointer arithmetic and dereferences, etc.). Update code to match new data structures. Begin merging changes from OpenMP code (sPuReMD) for preconditioning work.