Use Gittip.notification() instead of alert()

Some examples:
![](http://9k1.us/q;37/Screenshot_from_2014-04-01_12:22:15.png)
![](http://9k1.us/j6MY/Screenshot_from_2014-04-01_12:23:25.png)
![](http://9k1.us/jIc*/Screenshot_from_2014-04-01_12:25:53.png)
![](http://9k1.us/GlU4/Screenshot_from_2014-04-01_12:28:33.png)
![](http://9k1.us/LZmG/Screenshot_from_2014-04-01_12:30:48.png)