This has the following nice benefits:
* The 'Uuid' wrapper type is gone.
* 'Uuid' implements 'UriDisplay', 'FromUriParam'.
* The 'serialization' example merges in 'uuid'.
Resolves#1299.
...because loading up a Rocket while it's ignited is a bad idea.
More seriously, because 'Rocket.ignite()' will become an "execute
everything up to here" method.
The new examples directory...
* Contains a `README.md` explaining each example.
* Consolidates examples into more complete chunks.
* Is just better.
Resolves#1447.
Sergio Benitez