Adds getApparentTemperature() and getDewPoint()

The current conditions may include the apparent temperature and dew point, this commit adds get methods to access those properties.
Adds format ability to sunrise, sunset get methods

Makes sunrise and sunset get methods act like getTime method with optional format parameter.
Merge pull request #6 from trentrichardson/master

Adds getApparentTemperature() and getDewPoint()