Tahoe Code SVN development

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

add stress-free lattice parameter from the bulk model to the input parameters
of the surface model

added stress-free bulk lattice parameter as input parameter

Checking in files before updating code from Sourceforge. Updates include
using the asinh function instead of arcsinh in SSEnnLocDieterichT for
greater accuracy, and adding the ability to use a seed element for
homogeneous stress states.