add manifest documentation for uses-feature and supports-screens elements.
also update the navigation and manifest home page,
update the uses-sdk element to include new maxSdk and targeSdk attributes,
and add some sample code to DisplayMetrics to query the device for screen info.
added more information to the <uses-sdk> reference,
added a link to it from the <manifes> reference, and
revised some misleading information in the android 1.1 version notes
Original author: smain
Merged from: //branches/cupcake/...
Automated import of CL 146255