Extract simplex

[numberoverzero]

The 2.0.0 release removes plugins/router.py and the simplex dependency. Although probably not used anywhere, bottom.plugins.router.Router was part of the public API and so a major version change is required.

Aside from merge conflicts, this should simplify the work in #36.

Additionally:

• The bottom/examples/ folder uses a shared common.py to configure a client and attach the standard event handlers client_connect and ping.
• In place of the simplex router, the Extensions section of the User Guide provides a regex-based Router (which is just s/simplex/re/ the original router).
• Touch up README, sample code for readability.

[numberoverzero]

Your thoughts, @miedzinski?

[miedzinski]

I really like it. Good job!

[numberoverzero]

Thanks! Are you up for resolving merge conflicts on #36, or do you want me to give it a try?

[miedzinski]

I'll fix it.