Ping.fm support added

If you use ping.fm, you'll be glad to know that we've setup support their services. If you go to the tools page, you'll see a custom url that you can enter on your ping.fm account. Just go to: add application -> custom url, and paste your Publr ping.fm url there.

Additionally, there is a place in the settings page to enter your ping.fm application key so that anything you post on publr will also be published on your supported ping.fm services.