Fetch a users' email address along with the basic profile fields.

This is a proposed fix for https://jira.springsource.org/browse/SOCIALLI-24

I added a few of methods to the ProfileOperations interface / Profile Template implementation to allow a user of the library to get the user's email address along with the basic fields. I also added some unit tests an corresponding test data.

This could be useful since email address allows applications that are using Linked In as the authentication provider to be able to communicate with users directly, with the user's permission. In fact, basic profile + email address is one of the examples on the LinkedIn API documentation page in the section that explains authentication and authorization.

http://developer.linkedin.com/sites/default/files/gp-dialog.png