Move all smarty and path settings into the Smarty Extended class
the include files <admin|frontend>_set_paths.php and <admin|frontend>_smarty.php
are deprecated.
For special frontend smarty (which will be not used in future anyway) a
dedicated sub class to Smarty Extended with its own methods should be
created
Basic: recusrive array search has correct parameter declarations &
checks for null/empty/not string
IO: all unset are removed and null or init to array is used to reset
Update for other include pages with some missing default data
Because .inc style is deprecated and also dangerious as often not setup
correctly on the server all .inc files have been renamed to .php files.
All internall calls have been udpated.
