Fix on_start exception resulting in actor not being stopped

If on_start raised an exception the actor wouldn't be stopped and
unregistered.  Any messages sent to the actor wouldn't ever be
processed nor would the caller be informed that the actor isn't alive.
Add note about on_start exception behavior
Update changelog with on_start exception fix
Use verbose output to get name of hanging tests
Move "started actor" log message

It is now emitted right before the actor is started instead of right after. In
case the actor immediately stopped, the "started actor" log message may have
been emitted after "stopped actor", causing confusion.
Test logging of exception in on_start
Log exceptions in on_stop
Log exceptions in on_failure
Add support for using daemon threads (fixes #14)
Bump gevent dependency from 1.0b4 to 1.0rc2
tox: Run tests on Python 3.3 as well
pypi: Update short description
pypi: Bump dev status to stable
pypi: Add more Python version/implementation classifiers
docs: Bump copyright year to 2013
docs: New introduction (fixes #15)
docs: 'proxies' is closer to the API than 'typed actors'
docs: Fix typo in example
Use own domain for web site
docs: Fix typo