Infrastructure to convert Python ADJ_NBLOCK_DERIVATIVE_ACTION_CB callbacks to cfuncs, so that they can be registered.
Infrastructure to convert Python ADJ_NBLOCK_DERIVATIVE_ACTION_CB callbacks to cfuncs, so that they can be registered.

live-clones/libadjoint,live-clones/libadjoint,live-clones/libadjoint,live-clones/libadjoint