Miscellaneous bugfixes

1. Removes redundant call to buildThread() in mod_deletefile().
2. Firefox doesn't process call the onclick parameter of links when a link is middle-clicked, but Chrome does, which means Chrome users can't middle-click a moderator action to open it in a new tab. This commit fixes it by not doing anything in the onclick function if the link was middle-clicked.
3. mod_logout was missing a global and didn't use the redirect_http config setting.
4. mod_sticky and mod_bumplock both referred to the wrong variable while logging.
5. Don't show an empty filename if a post is missing its filename (such as if a post event removed it).
6. Two code paths in post.php's image processing were redundant. (Maybe the comment explaining why Imagick wasn't used was worthwhile.)
7. rebuild_timelimit config setting wasn't used after the mod interface rewrite.
8. mod_deletebyip was improved so it never rebuilds the same thread more than once.
9. The post() function's INSERT statement now specifies the columns it inserts into, so that way it won't explode if the table schema is changed.
10. The regex for fixing mod links in threads differed from the regex for fixing mods links in posts needlessly and was inferior.
11. A PDO parameter in a query in checkFlood() had the wrong type.