LFDS relies heavily on linux and x86_64 only hardware extensions. At the moment, this makes lfds "not portable", which ties nunc-stans down also.

To make matters more complex, to avoid memory leaks and corruptions the LFDS queue needs a small amount of hand holding to prevent leaks. The build process is complex due to lack of autotools and just generally complex.

To resolve this, I have created a datastructure wrapper, libsds that:

• uses autotools to build lfds, to make linking and building easier
• Is extensively tested with cmocka and multithread conditions.
• Contains a fallback mutex queue for platforms other than x86_64 linux.
• Contains the garbage collection abstraction so nunc-stans doesn't need to worry about it.

This is needed for #75 to port to FreeBSD