EmacsLisp interface to UUIDs.

There are only 2 functions that are useful for general Elisp
programming:

=== uuid-create  ===

Create a new UUID object.

Using version 4 (random) because it's likely easiest to
implement, plus it satisifies the privicy concerns of
wackos.

=== uuid-to-stringy uuid ===

Convert //uuid// to a string

=== uuid-string  ===

Make a string form of a UUID directly.

