Register: Work around GCC bug, that creates ambiguous overloads for deleted methods.
Register: Allow explicit construction by base class.
Register: GCC bug workaround fixed for non-GCC compilers.
Coroutine: Add ability to disable nesting level depth checking.
Architecture: Add Clang compiler detection.
Doxygen: Add some predefined macros.
Register: Add variadic template FlagsGroup class.
Replaces XPCC_FLAGS_GROUP.
Scons: Remove debugging `print`.