Tahoe Code SVN development

define isotropic elastic constants

(1) make constraints inactive, but still don't compute tractions with the
cz relations when the displacements of node pairs are both prescribed,
i.e., in the form of KBC's.
(2) take nodal values from the bulk and use them to update the state of the
zone when the cohesive relations are inactive (as the result of insufficient
damage).

(1) added iniital porosity parameter
(2) added UpdateState which overwrites porosity and damage with values from
the bulk

set number of nodes the same for both u and gamma_p until I can figure how
to use different interpolations for each

change mass type flag

corrected output for 2D simulations

added correction to the yield stress calculation when there is no rate
dependence, i.e., c_19 = 0.0

This commit was manufactured by cvs2svn to create branch 'BRANCH_solve_1'.

remove print statements and alter loop over elements to use predefined functions

change ordering of output variables. Displacement is now the first two output nodal variables.