Merge pull request #962 from ndtrung81/body-dem

doc/src/Eqs/pair_body_rounded.jpg

doc/src/Eqs/pair_body_rounded.tex

doc/src/JPG/pair_body_rounded.jpg

doc/src/Section_commands.txt

doc/src/body.txt

doc/src/fix_wall_body_polygon.txt

doc/src/fix_wall_body_polyhedron.txt

doc/src/lammps.book

doc/src/pair_body_nparticle.txt

doc/src/pair_body_rounded_polygon.txt

doc/src/pair_body_rounded_polyhedron.txt

examples/body/data.cubes

examples/body/data.squares

examples/body/in.body

examples/body/in.cubes

examples/body/in.pour3d

examples/body/in.squares

examples/body/in.wall2d

examples/body/log.9Jul18.body.cubes.g++.1

examples/body/log.9Jul18.body.cubes.g++.4