[Chicken-users] r6rs-bytevectors for chicken 5

[Diego A. Mundo]

With his permission, I've turned John Cowan's r6rs-bytevectors implementation:

https://github.com/scheme-requests-for-implementation/srfi-4/tree/master/contrib/cowan

into a Chicken 5 egg here:

https://github.com/dieggsy/r6rs-bytevectors

I'm aware of the separate C4 implementation of r6rs-bytevectors. I originally 
tried to port that implementation to C5, but I had some trouble with that and I 
think John's implementation is a little more favorable for a couple reasons:

- It's a little more recent and pretty much already written in C5 syntax - my 
changes were fairly minimal and trivial.
- It implements a couple flonum operations in C
- It has fairly extensive tests, which I've converted to use the test egg.

It'd be nice to have this in the egg repo for Chicken 5, assuming I haven't 
made any glaring mistakes.

- Diego A. Mundo