watch for filesystem events and rebuild the site

When the daemon is running (on OSX only, for now), we will watch for
filesystem changes and rebuild the site. If any store in the site
changes, including themes, the site is rebuilt.

Fixes #154
create type library for types and coercions

Having the coercions live right next to the classes creates a circular
dependency problem that I ran into trying to fix #122.
use Mojo::Log for logging

I had to establish a global "site" object in order to have easy access
to the logger. It makes sense, only one site can be active at a time
(for now), but it's still kind of ugly and I hope to find a better way.

Fixes #122
change all instances of print to say

We have say, we should use it.
fix new "redundant argument in sprintf warning"

I knew I used the "feature" that they added the new warning for...

Fixes #121
use bundles to remove extra Base modules

The Import::Base bundles, released in v0.009, allow for named sets of
imports, instead of requiring additional packages.

Fixes #128