UI changes (Kate F), New Features, Other Fixes

Continuing from #13 and #14

From @ELUTE / @YYGIRL:

>  * Implemented UI design from Kate F
>  * New battery indicator from Jon M
>  * Bigger fonts in general, especially for time
>  * New special value icons instead of special value numbers (??? instead of "10")
>  * Switched black and white backgrounds, to improve readability
>  * New space for T1D name
>  * Made JS faster based on inputs from John C and Christine D, to help with reliability and refresh problems
>  * Time and date are from system, so always up to date and watch can function like a watch
>  * More descriptive error messages
>  * Commented code in much greater detail
>  * Will publish FAQ to quickly identify problems and address faster

Also:

* The time will now update independently of the network
*  When we can't read data a clear message is displayed and the trend arrow and BG are removed