The Boost include and lib folders are cleanly separated from other libraries in
order to make future updates easier.

Related to issue #133

The NSIS package includes all the required applications, examples, headers and libraries.
The NSIS build folder is set to `build/winpackage` to avoid littering the main
build directory.
The artifact paths are corrected to avoid the warnings at the end of the
GitLab-Runner build log:
```
WARNING: build/bin/Release/*.dll: no matching files
WARNING: build/bin/Release/*.exe: no matching files
```

Related to #133

When a Powershell script is executed in the CI/CD, the error codes do not
propagate properly to GitLab runner. To prevent that, the simplest way is to include everything in the GitLab CI/CD script.

The build script is modified to run on the current Windows build
machines (including the Win10 VM).