Implement contacts

[epixian]

a Contact:

• belongs to: Organization
• has fields: id, first_name, last_name, title, work_phone, mobile_phone, email_1, email_2

[epixian]

Status update

• Add new Contacts via modal popup from Organization view
  • new Contacts set to "primary" if first Contact or if checkbox explicitly checked
• OrganizationContactsController handles all operations for better organization and code readibility

[epixian]

updated Organization.php:

• Organization::deleteContact()
  • added integrity check for attempted deletion of non-org contact
  • removes primary contact relationship if deleting the last contact, otherwise assigns new primary contact