DUE temperature sensor API

A note for posterity...
Markus_L811's code works great because he is reading the temperature every 10ms. If you wait longer between reads (say 1sec), you start to get garbage readings after 10 or so readings. But, if you make the raw measurement (the temperatur function) twice in a row when needed, it works fine. It takes about 90usec total for each temperature reading (with the double read).