issue/2122-reader-share

Fix #2122 - when sharing a post from the Reader, the shared text now includes the title and uses the post's short url if it has one.

![device-2014-12-18-132833](https://cloud.githubusercontent.com/assets/3903757/5493567/fbd0c6aa-86b9-11e4-9821-75aea474920a.png)