Move PrintRegion object storage to C++.
Add most of Layer class definition (except PrintObject ptr).
Add LayerRegion class definition.
Add most of PrintObject definition.
Complete Layer class def with reference to PrintObject.
Add forward declaration for PrintRegion.
Add Print class definition.
Add missing includes and forward declaration to Layer.hpp
Add SupportLayer class definition.
Add support_layers vector to Print class.
Add Layer.cpp with constructor/destructors.
Fix incorrect member name in comment.
Add typemaps for various Print and Layer objects.
Add LayerRegion constructor/destructor and REGISTER_CLASS.
Add Layer.xsp with empty definitions for Layer classes.
Comment out Perl class definition in Layer and Print objects, so C++ version is used.
Add REGISTER_CLASS calls for Print and PrintObject.
Rearrange Layer constructor params.
Add ::Ref classes for various Layer and Print classes.
Add Layer accessors (except regions array).