Port everything to use the new Contact-API.

This removes the old Contact object. Everything using that needs to be
adapted.

Contact-type features (ie. campaignion_supporter from the
campaignion_starterkit) need to provide a contact class via
hook_campaignion_contact_info().

Profile using any CRM functionality need to provide at least one
contact-type and set the 'campaignion_supporter_contact_type' which
defaults 'contact'. Hint: use "drush vset" or variable_set().

Failing to provide the default contact-type will lead to a
UndefinedContactTypeException being thrown.