move SWIG support to tools/swig folder

tools/swig/run_python_example.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+
+cat > example.py <<EOF
+from pylammps import *
+
+lmp = lammps_open_no_mpi(0,None,None)
+ver = lammps_version(lmp)
+lammps_command(lmp, "units real")
+lammps_command(lmp, "lattice fcc 2.5")
+lammps_command(lmp, "region box block -5 5 -5 5 -5 5")
+lammps_command(lmp, "create_box 1 box")
+lammps_command(lmp, "create_atoms 1 box")
+
+print("LAMMPS version ",ver)
+print("Number of created atoms: %g" % lammps_get_natoms(lmp))
+lammps_close(lmp)
+EOF
+
+PYTHONPATH=$PWD:${PYTHON_PATH-PWD}
+
+export PYTHON_PATH
+
+python example.py