Make C++ standard to be enable from cmake settings:
User will be able choosing C++ language standard by selecting cmake variable BUILD_CPP_STANDARD.
For correct working, CMAKE_CXX_STANDARD cmake built-in variable should be available.
To enable CMAKE_CXX_STANDARD, minimum CMAKE version has been updated to 3.1.
Available next standard items:
C++11
C++14
C++17
C++20
C++23
This issue consists from several steps to achive main goal:
1) Configuratiuon, CMake - allow selecting C++ standard.
2) Require minimum CMAKE version 3.1 (for enabling CMAKE_CXX_STANDARD).
3) More flexible CMAKE_CXX_COMPILER_ID identification (fixups previous commit!)
4) Add description of new CMAKE variable `BUILD_CPP_STANDARD` into documentation.
5) Update CMAKE requirements in documentation.
6) Set C++11 standard for several projects.
- samples/tools/TStandalone is removed, to build Inspector out of OCCT, CMake should use tools/CMakeLists.txt fileName
- samples/tools/TInspectorEXE is moved to tools/TInspectorEXE
- TInspectorAPI_Version.hxx provides compilation inspector with earlier version of OCCT.
