Describe installation under Linux and Windows

[max-rosin]

This PR resolves #518 .

• My suggestion follows the style and contributors guidelines.
• I have taken care about the documentation.
• I have done the DCO signoff.
• My changes generate no errors when passing CI tests.
• I have successfully implemented and tested my fix/feature locally.
• Appropriate reviewer(s) are assigned.

[max-rosin]

There are a couple of open questions:

• Are the any version requirements for prerequisite software like cmake?
• The original description of the installation of C++ for Windows seemed strongly geared towards VisualStudio. I tried to generalize that. Does it work like I described it?

[kmeids]

@pmai do you see any update or changes that need to be done?

[PhRosenberger]

• Should we mention that protobuf and osi versions must fit to the ones chosen within the tools?
• What about static vs. dynamic protobuf in Windows?
• Do we require specific minimum versions of cmake / protobuf?

[kmeids]

Output CCB 09.06.2021:

1. @pmai will provide a readme to enrich this section, for an easier windows installation process.
2. This would not hold the merge process and can be adapted afterwards

[pmai]

Using vcpkg to properly build the required configurations of protobuf on Visual Studio (here VS 2017):

• Install vcpkg as per the documentation, e.g. clone via git the bootstrap as needed

• English Language pack needs to be installed for VS 2017 for vcpkg to work

• Create a new triplet file for the required combination of static library linking with dynamic runtime (usually needed for dynamic linking to still work):
  I had to create a file named x64-windows-static-md-v141.cmake in the triplets directory with the following content:

  set(VCPKG_TARGET_ARCHITECTURE x64)
  set(VCPKG_CRT_LINKAGE dynamic)
  set(VCPKG_LIBRARY_LINKAGE static)
  set(VCPKG_PLATFORM_TOOLSET "v141")
  

  Note: only need the v141 suffix and setting of VCPKG_PLATFORM_TOOLSET to ensure VS 2017 is selected if you have newer VS installed (like I had).

• Now the protobuf libraries can be built automatically using:

  vcpkg.exe install protobuf:x64-windows-static-md-v141
  

• Once built, they can be automatically used in building the examples by specifying the triplet and toolchain file from VCPKG on the cmake configuration command-line:

  cd examples
  mkdir wbuild
  cd wbuild
  cmake .. -DVCPKG_TARGET_TRIPLET=x64-windows-static-md-v141 -DCMAKE_TOOLCHAIN_FILE=../../../vcpkg/scripts/buildsystems/vcpkg.cmake -G 'Visual Studio 15 2017 Win64'
  cmake –build .
  

The CMAKE_TOOLCHAIN_FILE must point to your vcpkg directory, which in my example was parallel to the osi-sensor-model-packaging directory…

This might complain somewhat depending on cmake and compiler settings, but builds without problems (and should support release and debug builds out of the box).

[kmeids]

Output CCB 09.06.2021:
@pmai will merge this pull request.