Added Mode filter and Thermistor Beta Calculation

Added options to run a mode filter on the analog read in addition to
smooth and an option to calculate temperature based on the Beta value of
the thermistor.  Mode filter works by setting modefilter to 1 and
specifying a num_reads. Beta calculation works by setting beta to a
nonzero number.
Changed Library Name

Added contributer and and changed library name and description to
reflect mode filter and beta value calculation.