Merge commit '4f82394af6486e1725ae6b6dd3b0334dcfc52747' into eclair-plus-aosp * commit '4f82394af6486e1725ae6b6dd3b0334dcfc52747': doc change: Add docs for SDK. Support new modular structure. In Android.mk, change @since level identifier to 5.xml, expose adt downloadable vars. Fix links that pointed to @sdkCurrent.