Using the AK 8973 datasheet modified the temperature code. Too many
bits were being used in the original get_temperature function. Also
added a method to return the temperature in Celsius.

Note: this is the temperature of a magnetometer not the room temperature.

Added swig bindings for the new get_temperature_in_celsius
Modified the example.c program to use the new get_temperature_in_celsius method.
Merge pull request #61 from rhololkeolke/fix-temperature-sensor-reading

Fix temperature sensor reading