- fix the 46 errors reported by the w3c html validator in appview.php?versionid=whatever
- fix the 97 errors reported by the w3c html validator in index.php
- removed appIdToName($appId) and versionIdToName($appId) from category.php
- replaced every occurence of appIdToName and versionIdToName with lookup_app_name and lookup_version_name
- improved performances (much less duplicated mysql queries)
- less code and better error handling
- informs the whole thread when posting new comment
- fix various bugs