Update logic for displaying Manage Profile button.

Only when a signed in user is viewing their own profile should they see a link
to manage their profile on the user show view.
Adjust the user profile cookbooks language logic.

A user should see the username of the user profile they are viewing if that
profile is not theirs when that user profile has no cookbooks in the different
tabs.
Merge pull request #390 from opscode/user_show_user_fix

User show current_user logic fix