This updates the hosting service paginator classes to check that the

subclasses are providing the correct values when returning a page of

results. This gives us assurances that the values will be compatible

across Python 2.x and 3.x.
The documentation has been updated to explicitly state the valid types.

The rest of the documentation for the file has also been modernized to

help make usage of these much more clear.

Unit tests pass.
Built the docs and checked them for obvious errors.