No real changes, just execute only the tests relevant for the section
being executed instead of always running the code loading PNG images
when running a section not using them at all.
This has the advantages of being a bit faster to execute (and the total
test suite run time does add up) and, more importantly, showing the
right amount of tests when executing a single section: e.g. now it's 1
in the simplest case, as expected, and not 5.
The disadvantage is, of course, slightly more code duplication, but it
doesn't seem a huge problem in practice and making each section code
more self-contained is arguably worth it.
Also, compensate for this somewhat by extracting all XPM definitions at
the function level: those are only initialized once (being static), so
there is no need to duplicate them.
Finally, also call AddHandler() once instead of once per section as
before.
d58f9bea72
