Fixes for tools to build on windows (MSVC)

[oyvindln]

Variable-length arrays are non-standard, so replaced it with vectors instead. Not sure if it was ideal to use that for arrays that large anyhow. They're currently re-created on every call to those functions which is a bit sub-optimal but not focusing on that right now.

[oyvindln]

WIth this the tools now build with MSVC on windows. I haven't ran the tests etc yet though, need to add some stuff to bundle dlls and/or build statically. Running ld-analyse from qt creator and opening tbcs seems to work with no issues at least.

What I did to build was to install MS build tools 2019 for the compiler, Qt for qt creator, and
vcpkg. Then use vcpkg to install fftw and qwt (which installs the rest of Qt) like so:

.\vcpkg.exe install fftw3:x64-windows
.\vcpkg.exe install qwt:x64-windows

Then create a new Qt kit with qmake from vcpkg in qt creator, and add this:

LIB+=D:\prog\vcpkg\installed\x64-windows\lib```
To "environment" under the kit options to make it find the libraries and include files.

After this it builds fine in Qt Creator provided the right kit is selected in project options and release mode is used (debug probably works fine too but installing qt took via vcpkg took hours since it has to compile it so only tested release.)

[oyvindln]

btw the removal of the GPL header from some of the EZPWD source files was from upstream, no idea why they did that but it's still GPL.