Code cleanup
Provide Network.{network,netmask,broadcast}_long() convenience methods
Fixed bugs in the host_{last,first} logic and __iter__ method, closing #18
Code cleanup
Moving to version 1.0.0

We are getting mature enough to call ourselves 1.0, there are no API changes
from the 0.x releases. Also, I have changed the numbering scheme to x.y.z, so
we can support patch level releases without having to release a new minor
version. A new major version will be introduced when non backward-compatible
API changes will happen.