Correctly parse all types of iCal durations

This was supposed to be fixed in 6ca2535 (ical.c: Simplify and fix
ical_durtime2long(), 2014-07-28) but some cases were not covered.

Reported-by: Håkan Jerning <jerning@home.se>
Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>
test/Makefile.am: Add missing test

We added ical-005 in f3fe3c8 (Gracefully handle all day events in iCal
imports, 2014-08-18) but forgot to add entries to the Makefile.

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>