installdeps: when module package install fails,

fall back to CPAN (used to do that, recent changes inadvertently removed it)
dist.ini: added Net::IMAP::Simple::SSL
Policy.pm: added domain get/setter
Report.pm: added metadata package, and setters for

the 3 top level report sections (report_metadata, policy_published, record)
added IMAP report retrieval and XML rework

dist.ini: added imap section
Receive.pm:
 - can now extract reports from a file or via IMAP
 - switched XML method to Xpath retrieval (less efficient, but also less fragile)