It seams that main Windows build problem was because of the big number of the C++ compilers installed on my PC.) All is simple and working without big problems on clear Windows installation:
1. Install MinGW with MSYS (
http://mingw.org/, use 64bit toolchain)
2. Install OCPWin (
https://www.typerex.org/ocpwin.html, use compiled with mingw package)
3. Add OCPWin bin directory to system PATH environment variable.
4. Open MSYS and navigate to qeditas sources
5. Fix the problem in sources, mentioned in previous post, for example change "/dev/urandom" to "urandom" and place non-empty file with name urandom near the qeditas.exe in the future.
6. Use usual configure & make to build qeditas.exe (set install and data directory in configure args)
That's all.
Now I'm trying to build Trent Russel's branch with leveldb.
What about dev/urandom: I hope to find universal way to get random numbers in OCaml, if there is no such way (it would be surprising) we can add C-based module to generate such numbers that will work on any platform.