Add "what's new" and "suggested_version_name" to App.

Note that the format is still screwey, the but it goes theough the same preprocessor as the description. So when app descriptions are fixed, so will this be.

Whats new is localized, and suggested_version_name is only set if there is a relevant suggested version.

Noticed while working on this that suggested version code in the metadata is a string, whereas each package's version code is an integer, so needed to cast the suggested code before comparing.