Current screen address area moved to public

[bigbigmdm]

This will allow you to define the memory area on the current screen from an external program

[Simsys]

I think the basic idea is good, as this option gives applications better control over the widget. However, we cannot implement it that easily.

1. We should turn these variables into Qt properties and document exactly what they mean.
2. We have to observe boundary conditions when setting the values. Is the desired value within the valid range (<0 --> 0, >= len -> len-1)? If we set the value bPosFirst, we also have to set the value bPosLast. If we set bPolsCurrent, it must be between bPosFirst and bPosLast, etc.
3. We need better names. The names are okay within the class, but not outside it. This must be clearly understandable. Incidentally, the _ at the beginning of the name indicates that it is a private variable. This is of course not acceptable for an external interface.

[bigbigmdm]

Hello, @Simsys !
Thank you! You know C++ so well I don't have such deep knowledge. I already did a comparison of two binary files in IMSProg and Binary_file_comparator just by pulling those variables into PUBLIC. Let's do it together properly...