AM: rm unused imports
AM: indent and whitespace
AM: API of libbgy3d.a will be in libbgy3d.h
AM: fix WITH_BGY3D build
AM: e_rism will hold RISM contribution, or zero
AM: this staff is not (yet) in GPL version
AM: if compiled WITH_BGY3D add RISM term

Add it to both energy and forces, but only if the *server* variable in (guile
bgy3d) module is trueish.  The search path in the runqm script needs to be
augmented to find that module. This is not yet automated.