Tahoe Code SVN development

(1) initialize some pointers to NULL
(2) name change natural_bc -> aps_natural_bc to avoid collision with
natural_bc defined in ContinuumElementT

fixed access default exception, but now get malloc

modified xml input format

get access fault exception in APS_AssemblyT destructor when run as -xsd in CW

small strain enhanced strain localization element updated for xml

compiles but not working

Bus error when run "tahoe -xsd"

corrected removing lambda degrees of freedom from center nodes

syntax needs to be changed because variables are now pointers to fields, not
fields themselves

further updates

still not compiling

headers and typos

-- converted to XML format
-- material modified to match J2 material models