Modal confirmation, CDN images

- Modal confirmation replace with something better open-classifieds/openclassifieds2#963
- CDN images open-classifieds/openclassifieds2#961
To build the URL instead of : core::config('image.aws_s3_bucket').'.'.'s3.amazonaws.com/

USage of core::config('image.aws_domain') ? well let me check it tomorrow, ok? I will send you an access key so you can test ;)