parse_url() attempts to parse Window file paths

Fixed by utilizing PHP's internal filter validation instead.

Example of unexpected parsing:

```php
C:\xampp\htdocs\contest>php artisan stapler:refresh Photo
Refreshing uploaded images...
Array
(
    [scheme] => C
    [path] => \xampp\htdocs\contest//system/Photo/photos/000/000/001/original/ba4a8fc0840011e3b64d12c7bfb8ccec_8.jpg
)
```
Merge pull request #29 from marsd/patch-1

parse_url() attempts to parse Window file paths