Moved all the new interface elements and materials to two subfolders under sm. (InterfaceElements and InterfaceMaterials) Also moved the converted interface material models (the old ones) to /sm/InterfaceMaterials/Old.

Also converted IsoInterfaceDamageMaterial_2 to IntMatIsoDamageTable and rewrote it to inherit from IntMatIsoDamage.
Moved isointerfacedamage02.(C/h) to sm/InterfaceMaterials/Old