New DialogFX

I would like to pull my fork of the DialogFX pop up, I redesigned the GUI with a .fxml file, and also updated the icons to GTK. You can see an image of the pop up below (The language is portuguese-br if you are curious :smile:).
![dialogfx_popup](https://cloud.githubusercontent.com/assets/3271143/4655527/008b5ce0-54c5-11e4-8c36-8c4d79a8a4e7.png)

Regards, 
Rafael C. Nunes.