Add xcas source code to obtain panography shared Focal polynomial solver.
Add xcas source code to obtain panography shared Focal polynomial solver.

Nazg-Gul/libmv,Nazg-Gul/libmv,petertsoi/libmv,Nazg-Gul/libmv,petertsoi/libmv,keir/libmv,SoylentGraham/libmv,petertsoi/libmv,libmv/libmv,rgkoo/libmv-blender,keir/libmv,SoylentGraham/libmv,keir/libmv,Nazg-Gul/libmv,SoylentGraham/libmv,rgkoo/libmv-blender,petertsoi/libmv,Nazg-Gul/libmv,rgkoo/libmv-blender,libmv/libmv,keir/libmv,libmv/libmv,rgkoo/libmv-blender,SoylentGraham/libmv,libmv/libmv,rgkoo/libmv-blender