Manually install wheels, otherwise bdist_wheel fails.
Deployment now happens on Python 2.7.
Updated the documentation.

This includes adding links to useful sites, and updating the examples section.
Adopted new fastnumbers module.

This module quickly confers strings to numbers, and will speed up
the natsort algorithm significantly (if it is installed). In case it is
not installed, a "fake_fastnumbers" module is added to natsort that
simulates the needed functions.

It is found that up to 30% gain in efficiency can be had by using
the fastnumbers module.
Updated .travis.yml.

Deployment will now be done manually... Travis-CI deployment was found
to be buggy.

Additionally, testing with and without fastnumbers will be done.