Lots of new features:
- Now logs energy (mWh and mAh)
- Multiple screens (use button to cycle)

Displays: min Voltage, max current, mWh, mAh, peak power, along
with relevant values at each of those points (current at min voltage,
voltage at max current, current and voltage at peak power, etc).

Serial output is unchanged for now, but I'll probably update this
next.
One more screen in big characters

Also now rounds the display of some readings to make screens
more legible.
Cleanups and add a "big reading" Voltage & Current screen
Forgot a "break" statement earlier...
Fix a few typos
Merge pull request #5 from elafargue/multiscreen

Multiscreen support 
Right now mA doesn't show decimals.
Update decimal handing for mA

-Added decimal to lower display
-Top display auto adjust if decimal needed
-Turned off debug by default
-ToDo: Long press clears peaks and energy usage
Added long button press to clear data

Long button press about 3-4 seconds
Clears all peak, min and energy usage data
Updated README with need TimerOne Library