Update MCP9804 library from 0.2 to 1.0

[FokkeZB]

https://github.com/hackscribble/hackscribble-MCP9804-library#10-9-december-2016

Relevant for us:

• [x] Use setMode() to shutdown and wake the sensor instead of _writeRegister16()
• [x] getTAFloat() has been renamed to getTA()
• [ ] ~setTUPPER() etc now take floats and return boolean to notify of failures~
• [ ] ~setHysteresis() and configureAlert() also return boolean to notify of failures~