Refactored CRM_Volunteer_Form_VolunteerSignUp to cache UF Group ID.
Refactored CRM_Volunteer_BAO_Assignment::createVolunteerActivity. Simplified parameter requirements. Added validation. Added return values.
First pass at postProcess for volunteer sign up form. Captures profile form input as well as built-in fields. A few todos remain.
Updated postProcess for volunteer log form to conform to changes to CRM_Volunteer_BAO_Assignment::createVolunteerActivity.
Merge pull request #69 from fjg-conflux/vol_signup

First pass at volunteer sign-up form postProcess. Refactored Assignment BAO create method.