Fix 0011041: set_status_threshold doesn't work on a per-project basis

We currently use access_get_status_threshold() inside access_api.php to
do all checks based on the set_status_threshold configuration option.
Hence this function works on a global level. It accepts a project ID
argument but doesn't actually use it!

This commit also fixes up some issues with the change status option
lists with respect to per-project configuration of set_status_threshold.