add Wind data access object
add Atmosphere data access object
add Condition data access object
- reorder methods in Feed.php in order of field appearance in the Yahoo! Weather API feed
- make call to Feed::fetchData() implicit when giving a location ID in the constructor
- extract feed loading and namespace registering from Feed::fetchData() into separate methods
- add fluent interface to Feed::fetchData()
- add usage of Condition data access object
- update inline documentation to reflect new package structure
- raise version number to 0.2.0