add "shutdown" button to the IDE

[SillyFreak]

At the moment, the only way to shut down the Hedgehog's Raspberry Pi is via a command prompt, so Raspbian is rarely shut down cleanly. A button should be added to the IDE to allow this.

The button should show a prompt asking for confirmation and, if acknowledged, a waiting screen showing an approximate time until shutdown and which RPi LEDs to observe.

I'll supply wait time estimates and LED details on request