#24 Show device age in device search view

lib/App/Netdisco/DB/ResultSet/Device.pm

@@ -16,12 +16,22 @@ will add the following additional synthesized columns to the result set:
 
 =item uptime_age
 
+=item first_seen_stamp
+
 =item last_discover_stamp
 
 =item last_macsuck_stamp
 
 =item last_arpnip_stamp
 
+=item since_first_seen
+
+=item since_last_discover
+
+=item since_last_macsuck
+
+=item since_last_arpnip
+
 =back
 
 =cut
@@ -36,9 +46,11 @@ sub with_times {
         '+columns' => {
           uptime_age => \("replace(age(timestamp 'epoch' + uptime / 100 * interval '1 second', "
             ."timestamp '1970-01-01 00:00:00-00')::text, 'mon', 'month')"),
+          first_seen_stamp    => \"to_char(creation, 'YYYY-MM-DD HH24:MI')",
           last_discover_stamp => \"to_char(last_discover, 'YYYY-MM-DD HH24:MI')",
           last_macsuck_stamp  => \"to_char(last_macsuck,  'YYYY-MM-DD HH24:MI')",
           last_arpnip_stamp   => \"to_char(last_arpnip,   'YYYY-MM-DD HH24:MI')",
+          since_first_seen    => \"extract(epoch from (age(now(), creation)))",
           since_last_discover => \"extract(epoch from (age(now(), last_discover)))",
           since_last_macsuck  => \"extract(epoch from (age(now(), last_macsuck)))",
           since_last_arpnip   => \"extract(epoch from (age(now(), last_arpnip)))",