tests/: Add basic iCal import tests

Tests ical-002.sh and ical-003.sh currently fail due to bugs in duration
and exception parsing.

Reported-by: Håkan Jerning <jerning@home.se>
Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

test/data/ical-001.ical

@@ -0,0 +1,12 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+BEGIN:VEVENT
+DTSTART:19020101T000100
+DURATION:P1DT9H17M0S
+SUMMARY:Calibrator's
+END:VEVENT
+BEGIN:VTODO
+PRIORITY:1
+SUMMARY:Nary parabled Louvre's fleetest mered
+END:VTODO
+END:VCALENDAR