Disable simulator.
Merge pull request #617 from makyo/disable-simulator

Disable simulator.

The simulator is no longer of much use to us in a development environment.  This disables it by default, though one can still turn it on using the hotkey or feature flag.
Cleanup of removed pyjuju tests.
Fade and highlight services on click.
Implement the three button states.
Review feedback.
Add a "no services" message.
Update service count in charmbrowser.