Adding all the work I have done so far in LAMMPS

So far I have performed some tests on FCC packings of spheres in an attempt to
validate granular LAMMPS using the analytical solutions of Thornton (1979).

These tests include axial strain conditions at a range of values of the coefficient
of friction for the gran_shm_history and gran_hooke_history pair styles and some
initial plane strain tests.

As I will be working on several machines it will be useful to have my work available
across all machines via git.

chris
Merge branch 'master' of github.com:chrisk314/Liquefaction