Only render comments if field is visible in view mode

This is part feature request and part bug report. I was experiencing an issue where this module was breaking Views pagers in views that displayed rendered user entities. Something related to the call to comment_node_page_additions() in user_profile_comments_user_view(). This patch only retrieves rendered comments if the user_profile_comments field is set to visible in the view mode thereby skipping the offending function call when required. So an admin can switch them on for the full view mode and switch them off for teasers etc. This will be a performance improvement as well for views that display a list of rendered teasers as they won't have to retrieve comments for each item. It also may break some existing configurations :(.