Update export comments in D3 module
Update examples to work with Elm 0.12

Closes #5
Update README
Update README

Completely update the code example, and update the explanation of
render, since its arguments have changed.
rename static_ to static

The latest version of Elm allows you to use reserved words in JavaScript
as identifier names, so use static instead of static_. That _ is
awkward.
event: Stream type, and folde

A Stream is a Signal of events that can be created without providing a
default value. Instead, the folde function's accumulator is in essence
used as the default value.
event: Add handlers for all DOM 3 mouse events
event: update import syntax for latest Elm version
event: rename start to stream
event: add clicks example