Added email link to social sharing

The social sharing button now has an 'Email' option. I had to split the colors on the pointer arrow but I think it still looks nice (screenshot below).

For now I am using the post title as the subject, and then using the body of the post as the body of the email followed by a link and attribution. I can change it if there's a different message you'd like to use.

Share popup:
![screen shot 2014-02-09 at 10 45 28 am](https://f.cloud.github.com/assets/111194/2120271/aa71c094-91a9-11e3-87ac-6f6cffbce119.png)

Email it produces:
![screen shot 2014-02-09 at 11 52 44 am](https://f.cloud.github.com/assets/111194/2120420/19d16bf2-91b3-11e3-8ab6-c73ced635c27.png)




To check it out you can just use 'git checkout social-sharing', which should pull down what I have and switch you to that branch. Then after merging on Github you can switch back to master 'git checkout master' and then 'git branch -D social-sharing' to delete that branch locally.