Fix build issue where config.h.in is only generated once (for sPuReMD) => common file across all versions.

Build toos: refactor to remove recurisve Makefiles. Fix issue with OpenMP flags being overridden when user supplied value for CFLAGS variable.

Build systems updates for sPuReMD, PuReMD-GPU, and PG-PuReMD (use safer optimization level defaults).

PG-PuReMD: fix function pointers for bonded forces. Declare constants appropriately in bonded force computations. Fix sym_index computation for bond list. Other code clean-up.

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: add deallocation routines at simulation termination for aiding with validating memory management.

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.

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

PG-PuReMD: fix charge matrix allocation issue. Update CUDA code to reflect data structure changes. Begin removing global variables. Seperate struct declarations and definitions to avoid circular data dependencies when refactoring data structures. Small I/O updates.

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.

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

All: fix issue with pi bonds being incorrectly computed in bond orders. Patch originally submitted to LAMMPS mailing list by Tomas Trnka, SCM (refer to Issue #837 on Github).

PG-PuReMD: fix error due to function prototype change. PuReMD: fix issues with GCC new inline behavior, fix reax_list bugs. sPuReMD: change exit code to zero.

PG-PuReMD: complete memory changes. Remove max register per CUDA function option in build. Other misc. changes.

PG-PuReMD: only perform device-side reductions on energy at requested update energy frequency. Fix trajectory file output. Add num. retries of main simulation loop to log file. Other refactoring.