This makes the version tests more readable (though also more verbose).

It is unreliable, and cleared for no apparent reason if when buttons
are still held.

Issue #2577

Bumping them for every release just adds too much git
noise and history blowup.

Closes #2391
Closes #2387

Issue #2560

Issue #2564

So that the added zero-width space doesn't confuse readinput, even
if some other event handler messed with the selection in the meantime.

Issue #2566

Issue #2503

Issue #2503

Issue #2556

Issue #2557

Issue #2551

Issue #2554

Add shape-image-threshold and shape-margin.

Issue #2542

Issue #2537

Closes #2533

Fix the condition when XML styling should be invoked.
Also add test cases.