Wixel Battery Display!

[syntaxerr66]

• Added Wixel battery display!
• Added ability to set minimum and maximum millivolt settings since there is a 0.3v variance in the cutoff point for the Adafruit batteries
  • PLEASE NOTE if the battery is shutting down before 0% OR you are charging over 100%, talk to me (syntaxerr66 on github) so I can try and get your voltages.
• Added option to prevent phone from sleeping
• Fixed stupid merge conflicts
• Fixed other issues

TODO:

• Add color for battery levels
• Add fudge factor for battery levels
• Move wixel status to separate model?

[syntaxerr66]

I added a try-catch for exception handling of in case the 2nd element of the array wasn't transmitted, and it'll show it on the home screen that it was missing.

[StephenBlackWasAlreadyTaken]

also thoughts on using the same shades as the rest of the app (orangeish and dark redish and white in place of green?) I forget the exact values but we should probably constantize them somewhere, you can find them in the BgGraphBuilder class

[syntaxerr66]

Well crap, I didn't realize my experimental stuff would get shoved into the PR. The popup and colors and stuff weren't supposed to be part of the PR. Didn't know that if I push to my master, github automagically incorporates it. I learned something new today.

I'll make the changes you noted (I meant to do notification, but was tired and wanted to just make something work), and the colors.

[StephenBlackWasAlreadyTaken]

Looks good! 2 minor issues still, we need the migration that added the battery level column (you can roll them both into migration 21 because presumably no one currently running this has one and not the other?) and we have some merge conflicts again