Failed inclusions when run via cmdline

`php /full/path/to/index.php cron/index` fails as the app relies on being executed in the "public dir"

Even if not strictly necessary (a `cd` could solve) I suggest to use only fully qualified paths in the scripts in order to have a more portable behavior ..

just define a `BASE_DIR` (using `__DIR__`) constant and refer to it every time including or requiring files

my 2 cents
