We don't need to do this manually for RCT2 here, the parser does this in
a more complete way for us already.

KPOPPLER_VERSION isn't defined in that case, so using that in an unguarded
header is a problem.

In case of code-sharing the booking number can consist of multiple codes from each
airline, e.g. "ABCDEF/GHIJKL (Other Airline)"

Reviewed-By: vkrause

This should fix some test issues that appeared with Qt 5.14 in the app.

Summary:
state->getPath() now returns a const GfxPath, and the methods
we are calling on it are indeed const now.

But they were not const before, so we can't just use const
unconditionally here, hence the version check and the #define.

Test Plan: Builds

Reviewers: vkrause, aacid

Reviewed By: vkrause

Subscribers: kde-pim

Tags: #kde_pim

Differential Revision: https://phabricator.kde.org/D25644

This fixes mis-detection on reservations emails that contain a bogus 3
digit year number.

Happens e.g. with PDF-looking but invalid data, but also for password
locked PDF files.

This fixes the build with Poppler 0.83.

Since a recent change in KCalendarCore this triggers invalid reads, so
set an actual time zone, this has no practical impact on what we are doing
here anyway.

Usually that's the same as we get from other sources, with the exception
of Iberia it seems, which then breaks merging.

Also, add better diagnostic infrastructure for the comparison functions,
to replace the current local ad hoc debug output, same as already done
for the validator.

This simplifies the code and allows us to forward information about DB
Upgrade tickets (which use RCT2 tokens that the generic extractor
recognizes).

We use this to add a short human-readable description for "addon" tickets,
eg. upgrades or seat reservations for another ticket. This allows us to
distinguish those in the UI, as we cannot merge them into a single element.