modularizing BangleJS

So i did break out the barometer. I also broke out the accel,compass and touch. I did this fairly quick, so there might be parts that need to be moved over. I plan to do a second/third pass through it when moved the easy parts over. I put it on a new branch called quick_rewrite

So moving the barometer took me a little bit because i got confused on how the SPL0 worked across versions. So you can see the barometer code here

• barometer libs - supporting libs
  
• SPL0 driver
  
• barometer jswrap file
  
• barometer impl - Holds all the functions that can be overwritten and hold many of the states. So idle,init,on,off
  
• Bangle 2 device defines
  
  

Another consideration is it's not just Bangle.js that has sensors (Puck.js/Microbit/etc have them too) and in an ideal world we'd be able to reduce duplication there too - but I think possibly that one's just a step too far for the moment.

I think this would be awesome! I didn't dare go down that route because i know i would break something. Sounds like a fun thing to experiment with a new piece of hardware and then maybe back port some of the idea back to it.

There's probably a good middle ground between all-out abstraction and the current insanity that is jswrap_bangle.c though.

So i just found that there's all these "middle ground file" in the misc. For things like heartrate and gps. I just started to look at these things next. So they might be a middle ground somewhere there.

@Gordon