Some clean up of the struct constructor interfaces for color-spinor field orders.
CG solver has no tolerance for consecutive reliable update residual norm increases
Added half precision support to spinor packing routines which simplies cudaColorSpinorField routines.  Removed genericCopy routine using ColorSpinorFieldOrder class hierachary, now uses the spinor packing templated routines.  Precision fix for half precision clover packing in clover_field_order.h