Tahoe Code SVN development

start if split integration code

1. Changes to modulus calculation for quadratic convergence using element stiffnesses

temporarily use finite difference approximation to c_ijkl

corrected stiffness matrix calculation

1. Added accessor function for fSurfaceThickness (thickness of volume to subtract off) in FCC3D_Surf.

1. Added FormLHS command. Compiles, runs, does not converge. Debugging to ensue...

(1) corrected computation of shape function derivatives
(2) finished calculation of nodal forces

partial implementation of surface forces and stiffness

1. Modify stress, modulus and energy density calculations to account for bond energy splitting for surface clusters

typo