Split out the DBUS server logic to its own module

Helps clean up our main entry point.
Add a basic hello-world web server
Structure pysprinklers as an installable module

This includes moving everything into pysprinklers,
the module subdir, and adding a simple setup.py
file. This was necessary to make imports work
when I split out the platform.

Incidentally, this splits out the platform. The
platform is the module in charge of basic functionality
like talking to the DB or UBW. Since this is
very common between the webserver and glib, it makes
sense to factor it out
Fix JSON serialization failure on datetime objects