sPuReMD: fix GMRES bug introduced from previous refactoring. Explicitly link OpenMP for library. Refactoring to remove global variables. Remove unnecessary OpenMP barriers after single regions.

sPuReMD: fixes to remove compilatoin warnings. Replace standard library functions with safer versions to avoid buffer overruns. Safer use of placeholders in format strings for printing.

sPuReMD: fix bug in GMRES where vector inputs and outputs to apply_preconditioner were being overwritten. Refactor OpenMP code in GMRES.

sPuReMD: split into library and driver for, e.g., optimization integration. Fix bug with interaction lists being allocated for hydrogen bonds when no hydorgen atoms present. Fix minimum allocation size of 3-body lists (uncovered with small lithium geometries). Refactor naming of conflicting data structures. Update .gitignore.

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.