Add support for BLE meat thermometers for less soldering

[bobpaul]

This was described in a comment on #149, and I thought it would be a good idea to add it here so it's not forgotten:

Basically the idea is use a cheap BLE meat thermometer with several inputs ( @faisalhusain007 mentioned one with 6 probes for $20 ) as meat thermometers to PiFire. Someone could use this in a build instead of using the onboard ADC. PiFire would then make the values available via its webapp and use them for cooking modes that utilize the meat probes.

[nebhead]

This is definitely still in the queue. I had recently come up with the concept of 'transient' probes which is more-or-less implemented in the latest development branch. This would allow a probe device to be transient, meaning not always there which might be the case with a bluetooth device. That said, I haven't yet purchased any of these devices nor have I invested time to dig into the code to support them yet. In summary... it's coming someday, but don't hold your breath for it to happen soon.

[palmtreefrb]

For the "Meater" bluetooth probes there is a python library here. It works quite well. https://github.com/nathanfaber/meaterble

[nebhead]

All - This is now implemented on the development branch (v1.9.0). Just pushed the Meater Pro support yesterday. It's still very experimental, but if you have any Meaters (I do not, so I am not really able to test), please give it a spin and let me know.