Remove unused files

remove docs/
remove extras/
remove zc_install/
remove nddbc.html
remove page_not_found.php
remove install.txt
remove robots_example.txt
remove deprecated editors_list.php
remove classes we do not use
remove unused auto loaders
remove old sql upgrade scripts
remove index.php
add Kerrin Hardy image pack
[STRICT] remove duplicated constants
remove phpbb integration
remove some duplicate defines()
[COMPAT] remove locale and date defines we define
[STRICT] defaults for index_filters/default_filter.php
[STRICT] _SESSION[customer_id] check
[STRICT] check for undefined vars in includes/modules/attributes.php
[STRICT] check for no discount fields in modules/products_quantity_discounts.php
[STRICT] customers_id check in product_info/header_php.php
[STRICT] undefined vars in product_listing modules
[UNUSED] remove unused PHP_SELF check from tpl_modules_downloads.php
[STRICT] replace $PHP_SELF usage with $_GET[main_page] in tpl_currencies.php
[STRICT] isset() checks in functions_lookups.php
[COSMETICS] remove welcome message
[PERFORMANCE] remove unused code from footer module

Symfony's web debug toolbar does a better job
[STRICT] check  undefined var in ezpages_bar header/footer
[UNUSED] truncate includes/application_bottom.php
[UNUSED] remove unused tell_a_friend email template