Tahoe Code SVN development

Adding new derived class enhanced strain element with non-constant
friction. Updated base classes to better handle inheritance, breaking out
some functions, etc.

Updated to correctly calculate tangent stiffness for case when residual
cohesion goes to zero. Sometimes (though rarely) the answer is simple.

Lots of wordk. Updated to actually check for yielding along shear
band. Made sure slip direction was dialtatant. Track residual cohesion and
do not allow this to go below 0. Tried to create a routine to track
stiffness on step where cohesion does go to zero, but this gives only
linear global convergence. Updated to handle reverse loading and guarantee
that jump is positive along slip direction.

maintenance commit

updates for dissipation factor calculation

using AutoArrayT for normals, slipdirs,

attempt to use dissipation to determine normal

use new IsLocalized function that returns detA and dissipation for each normal

not completed tested

over-ride new IsLocalized function in SolidMaterialT

use reference for detA

use RowCopy instead of RowAlias for fetching arrays from dArray2DT types