[Python-ideas] Add __main__ for uuid, random and urandom

[Michel Desmoulin]

It's dangerous to talk about a new feature the 1st of April, so I'll
start by saying this one is not a joke.

I read recently a proposal to allow md5 hashing doing python -m hashlib
md5 filename.

I think it's a great idea, and that can extend this kind of API to other
parts of Python such as:

python -m random randint 0 10 => print(random.randin(0, 10))
python -m random urandom 10 => print(os.urandom(10))
python -m uuid uuid4 => print(uuid.uuid4().hex)
python -m uuid uuid3 => print(uuid.uuid3().hex)