project browsing pages don't honor the "active compatibility terms" setting

In IRC, killes asked me if we could hide any project nodes from the browsing pages if they only had a 4.6.x release (e.g. http://drupal.org/project/citizenspeak not showing up at http://drupal.org/project/Modules/category/66). I thought the Active Drupal Core compatibility terms checkboxes at http://drupal.org/admin/project/project-release-settings would solve this, since removing a term from the "active" list means you can't filter by that version anymore, etc. Unfortunately, there's a bug in project_page_overview in project.module where it doesn't use this setting when filtering release nodes when browsing by all versions.

Furthermore, there's a bug that when you filter by all versions, we don't discard unpublished release nodes. :( So, we end up violating what I thought was the semantics, that if a project has no published releases, it doesn't show up in the browsing pages. Currently, it does. To test this (and since killes doesn't maintain it anymore), I unpublished both of the releases for http://drupal.org/node/68898 (which are 4.6.x only). And lo, Mailcommand still shows up at http://drupal.org/project/Modules/category/66.

Totally untested, but I'm pretty sure the attached patch will solve both problems.