Removing old patch number checking code.
Revert "Removing old patch number checking code."

This reverts commit f858b35e433529e9a47ece132bef80c01d15e0e5.
Flipping logic so site/settings table check defaults to site. Should help with failed patch 210s.
Fixing nZEDb_COVERS definition, now Settings is main Db access class.
Flipping logic in Sites so site is the default table.
Fixing typo of Sites class in PostProcess.php
Changing Sites to use Settings for creating nZEDb_COVERS constant, so that it only occurs in one place.
Refactoring Settings code to simplify getting a setting when a simple setting name is requested.
Fixing some references to $this->table.
Adding missing parentheses to db->table calls in Sites.