A netlink-based user-space crypto API

The advantage that the sockets API has over ioctl is that the former provides a single, standard, already implemented and tested method of marshalling and unmarshalling parameters kernel-side.

The fundamental problem of the ioctl interface is that every implementer of the interface must re-implement that parameter marshalling - for every arch. There are plenty of ioctl()s that *still* don't work properly for IA32 callers on x86-64 arch.