Styles upd
FileDB improvements

Changes:
 - `'storage/db/'` to `static::$storage_dir`
 - overall increment / decrement improvement

Added:
 - save()
 - `create($data)` /* @var array OR object $data */

Updated:
 - find() /* Now returns $this with $this->key, where 'key' is column
name */

Example:
$result = Test::find(1);
echo $result->id; /* Will show 1 */ etc.