GitLab

Separated hardware query functions into a separate file.  CPU platform checks for the correct hardware.

Created API and reference implementation of restricting CustomNonbondedForce to selected interaction groups

Converted the routine for identifying molecules from a recursion to a loop.  This avoids stack overflows with very long linear molecules.

Using a const Vec3& instead of three doubles for the AnisotropicBarostat API.  Still figuring out SWIG issues.