Add the ability to enter text link to profile vkontakte, not just ID

Test scenario:

1. Open JCommune and Sign in as a user with EDIT_OWN_PROFILE
2. Go to profile.
3. Press Edit button.
4. Add contact with type "Vkontakte" and Contact value which consists with Latin letters, numbers, "." or "_".
5. Press OK button again.

AR: Contact isn't added with error message. Look on screenshot

ER: The contact will add successfully.

Node: Look on screenshot, there displayed allowed characters which may used in profile link of vk.