This commit cleans up the primary interface, and introduces two new methods that can be (are) used by core and the ident CLI:

• fingerprint_service: this method takes an ip and a port, and runs the appropriate checks
• fingerprint_uri: this method takes a uri, and turns it into an ip/port combination that can be sent to fingerprint_service
• list_checks: this method generates and lists all checks ... this is handy so we dont need to have clients directly interface with each protocol when generating a list of checks