Platform, add-on and doc packages used to use Api Level to figure out upgrade logic. This is replaced by AndroidVersion to properly handle codename versions.
Using the Eclipse projects for ddmuilib. ddmuilib requires SWT to compile. SWT is available in the depot under prebuild/<platform>/swt Because the build path cannot contain relative path that are not inside the project directory, the .classpath file references a user library called ANDROID_SWT. In order to compile the project, make a user library called ANDROID_SWT containing the jar available at prebuild/<platform>/swt.