Rename `Type\IntegerValue` to `Type\Integer`. It was originally named
`IntegerValue` because static analysis sees `Integer` in docblock
annotations and treats it as the native `int` type. `Integer` is not a
reserved word in PHP, so it should be named `Integer` for consistency
with other types in this library. When using it, a class alias prevents
static analysis from complaining.
Function api is a set of simple autoloaded functions to create uuids proxying the Uuid class static methods.
They provide easy and clean ways of just creating string represented uuids instead of the class.