title: VSCode not using Vcpkg acquired libraries
body: <p>For some reason, VSCode is not able to see headers inside Vcpkg's installed libraries directory. I am using CMake build system on Ubuntu 17.04.
  I am getting errors like:</p>
  
  <pre><code>[GCC] GL/glew.h: No such file or directory
  </code></pre>
  
  <p>My CMakeLists.txt looks like this:</p>
  
  <pre><code>cmake_minimum_required (VERSION 3.8)
  set (CMAKE_CXX_STANDARD 17)
  
  project ("RubeusCore")
  
  FIND_PACKAGE(OpenGL REQUIRED)
  
  # Include sub-projects.
  add_subdirectory ("RubeusCore")
  </code></pre>
  
  <p>And RubeusCore/CMakeLists.txt is this:</p>
  
  <pre><code>cmake_minimum_required (VERSION 3.8)
  
  link_directories(Source/)
  
  file(GLOB_RECURSE SOURCES
      Source/*.cpp
  )
  
  # Add source to this project's executable.
  add_executable (RubeusCore "RubeusCore.cpp" "RubeusCore.h" ${SOURCES})
  
  target_include_directories(RubeusCore PUBLIC ./Include)
  include_directories(${OPENGL_INCLUDE_DIRS})
  
  target_link_libraries(RubeusCore ${OPENGL_LIBRARIES})
  </code></pre>
  
  <p>.vscode/c_cpp_properties.json:</p>
  
  <pre><code>{
      "configurations": [
          {
              "name": "Linux",
              "includePath": [
                  "${workspaceFolder}/**",
                  "${vcpkgRoot}/x64-linux/include/"
              ],
              "defines": [],
              "compilerPath": "/usr/bin/g++",
              "cStandard": "c11",
              "cppStandard": "c++17",
              "intelliSenseMode": "msvc-x64"
          }
      ],
      "version": 4
  }
  </code></pre>
  
  <p>Also, I have specified the Vcpkg toolchain file in CMake once.</p>