title: includePath in c_cpp_properties.json not working in VSCode for C
body: <p>I'm working in VSCode with the C/C++ extension on Ubuntu 18.04.</p>
  
  <p>I'm trying to include gmodule.h and it raises the error <code>gmodule.h: No such file or directory</code> on line 2, character 10 of the main file.</p>
  
  <p>So, the problem lies with gmodule.h being not in /usr/include but in /usr/include/glib-2.0. Realizing this, I added this folder to the includePath variable in c_cpp_properties.json. However, it still raises the same error.</p>
  
  <p>When using <code>#include &lt;glib-2.0/gmodule.h&gt;</code> instead of <code>#include &lt;gmodule.h&gt;</code>, it does work but this only shifts the problem to gmodule.h itself, as other includes that lie in the glib-2.0 folder still don't work inside of gmodule.h.</p>
  
  <p>All in all, the problem is that add to the includePath in c_cpp_properties.json doesn't change anything and I want to know how to make this work, since I would like to use gmodule.</p>
  
  <p>c_cpp_properties.json:</p>
  
  <pre><code>{
      "configurations": [
          {
              "name": "Linux",
              "defines": [],
              "compilerPath": "/usr/bin/gcc",
              "cStandard": "c11",
              "cppStandard": "c++17",
              "intelliSenseMode": "clang-x64",
              "includePath": [
                  "/usr/include/glib-2.0/*"
              ]
          }
      ],
      "version": 4
  }
  </code></pre>
  
  <p>for now I'm just trying to include gmodule.h and not do anything with it yet, so this is my main file:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;gmodule.h&gt;
  
  int main() {
      printf("hai\n");
      return 0;
  }
  </code></pre>