[bug 881792] Add Mozillians field to user profile

Create a Mozillians profile field for adding link to user's Mozillians
page.

Need to add icon for Mozillians when displaying the link on user profile.

Signed-off-by: Kaustav Das Modak <kaustav.dasmodak@yahoo.co.in>
Merge pull request #1469 from kaustavdm/mozillians-field-881792

[bug 881792] Add Mozillians field to user profile