sw-collector: Iterate through history logs

The logrotate function causes the apt history to be split into
several parts at arbitrary points in time. If history.log only
is parsed then some package installation changes stored in
zipped backup history files might get lost.

Thus sw-collector now searches all backup history files until
a date older than the current event stored in the collector.db
database is found, so that no entries get overlooked.

testing/tests/tnc/tnccs-20-ev-pt-tls/evaltest.dat

@@ -17,8 +17,8 @@ alice::cat /var/log/daemon.log::accepting PT-TLS stream from PH_IP_CAROL::YES
 alice::cat /var/log/daemon.log::SASL PLAIN authentication successful::YES
 alice::cat /var/log/daemon.log::SASL client identity is.*carol::YES
 alice::cat /var/log/daemon.log::user AR identity.*carol.*authenticated by password::YES
-alice::cat /var/log/daemon.log::received software ID events with ... items for request 9 at last eid 2 of epoch::YES
+alice::cat /var/log/daemon.log::received software ID events with ... items for request 9 at last eid 3 of epoch::YES
 alice::cat /var/log/daemon.log::3 SWID tag target::YES
-alice::cat /var/log/daemon.log::received software inventory with 3 items for request 9 at last eid 2 of epoch::YES
+alice::cat /var/log/daemon.log::received software inventory with 3 items for request 9 at last eid 3 of epoch::YES
 alice::cat /var/log/daemon.log::successful system command: ssh root@moon.*logger -t charon-systemd -p auth.alert.*host with IP address 192.168.0.100 is allowed::YES
 moon::cat /var/log/auth.log::host with IP address 192.168.0.100 is allowed::YES

testing/tests/tnc/tnccs-20-ev-pt-tls/hosts/carol/etc/pts/collector.sql

@@ -23,17 +23,17 @@ INSERT INTO sw_identifiers (
 INSERT INTO sw_events (
   eid, sw_id, action
 ) VALUES (
-  2, 1, 2
+  3, 1, 2
 );
 
 INSERT INTO sw_events (
   eid, sw_id, action
 ) VALUES (
-  2, 2, 2
+  3, 2, 2
 );
 
 INSERT INTO sw_events (
   eid, sw_id, action
 ) VALUES (
-  2, 3, 2
+  3, 3, 2
 );