Use key_name instead of link_id
Some entities do not have a link_id, but all entities are guaranteed
to have a key_name (or an id).
Third-party code that is *not* part of the application image (the Google App
Engine SDK in trunk/thirdparty/google_appengine, for example) belongs in
trunk/thirdparty. For third-party code that *is* part of the application
image, see the notes in trunk/app/README.
== THIRD PARTY LICENSES ==
Third-party code must also include a license text file, named LICENSE or
COPYING, in the package subdirectory. If the third-party package subdirectory
is maintained automatically with a tool such as svn_load_dirs.pl (which
removes files, such as license text files, that were added later to the
"target" directory), place the license text file in the trunk/app directory
and add the package name as a suffix.