Recent msys version does not find libngspice-0.dll, only
libngspice-0.dll.a when using find_library.
When not found, a find_file is made, instead of find_library.
Some developer scripts ended up in the demonstration scripts directory
that was bundled with builds. This moves them to the build_tools
directory and updates the associated Documentation
Fixes: lp:1815891
* https://bugs.launchpad.net/kicad/+bug/1815891
Adds a link-time dependency for libngspice, so that other tools may
detect ngspice as a KiCad dependency.
The library is still loaded with dlopen() as it gives a way to reload it
in case of problems. The DLL name is recognized during CMake
configuration and used to load the library at runtime.
jean-pierre charras
Seth Hillbrand
Maciej Suminski
Chris Pavlina