User List and User Profiles

-renamed "list users" to "User Directory"
-added user profile page, so that you may view other users in the website
-added "privateProfile" boolean field to user model
-users can now make their profile private, hiding research interests, contact information, and portfolio in user directory. This can be done from the "edit profile" page.
-Added various methods to UsersController to achieve similar functions of cleaning up portfolio for viewing in profile page