[Feature Request] Packeta Plugin - check if Z-point is selected

[PhocaCz]

Packeta Plugin - check if Z-point is selected https://www.phoca.cz/forum/viewtopic.php?f=44&t=63845&p=172387#p172387

[sdrave]

Hmm, such solvers might be useful in some places. (For instance, the scalar product operators need to be inverted for many different right-hand sides.) I do not think I will have time to look into this in the near future, but I will leave the issue open ..