removed internal methods from public Display interface
printDegreeUnit takes location - saves 30 bytes
use printAt - saves 62 bytes
Display::printAt -> Display::printAt_P
Added printAt functions to DisplayLCD
Replaced use of itoa with sprintf_P (saves 50 bytes)
Overwrite longer old numbers with spaces.
Merge branch 'feature/dynaconfig' of github.com:m-mcgowan/brewpi-avr into feature/dynaconfig

Conflicts:
	brewpi_avr/DisplayLcd.cpp
	brewpi_avr/DisplayLcd.h