Use default 9600 baud rate

The baud rate of 57600 was causing some stability issues. The ATtiny84's
internal oscillator is too sensitive to the environment (mostly
temperature) to use such a high rate. The default of 9600 should be just
fine now that only one single byte is being sent for every byte
received.
Don't restart the Bluetooth module at boot

Since we aren't changing the baud rate, we no longer need to reset the
Bluetooth module at boot
Merge pull request #12 from codefox421/master

Use HC-06 default baud rate