Fix missing global post on save

When Quick Edit is used the `global $post` variable is non-existent
resulting in an ugly warning being thrown, messing the layout and making
folks unhappy.
Fix pages hyperlink in common settings

The URL was wrong and was not echoed out resulting in a completely
broken link.
Fix ACL SQL error when ACL is empty
Warning on unset roles in member settings

Non-existent array key produced two warnings. Fixed this.