Add native bridge, starting from RTCDataConnection

We want to avoid blocking cross-thread calls that node-gtk provides. So
we create a sort-of thin wrapper library that marshalls the events
natively from WebRTC event thread to main thread.

.gitignore

@@ -1,2 +1,5 @@
 /node_modules/
 /lib/
+/lib-native/
+/src-native/compile_commands.json
+/src-native/.cache/

.ts-for-girrc.js

@@ -3,7 +3,7 @@ const uniq = require('lodash/uniq');
 
 const GstBuildDir = process.env['GST_BUILD_DIR'];
 
-let girDirs = ['/usr/share/gir-1.0'];
+let girDirs = ['/usr/share/gir-1.0', `${__dirname}/lib-native`];
 
 if (GstBuildDir) {
   // Various Girs are spread accross build directories. Use `find` to
@@ -15,16 +15,21 @@ if (GstBuildDir) {
     { encoding: 'utf8' }).stdout.split('\n');
 
   // Specify the discovered directories first.
-  girDirs = [...uniq(dirs), '/usr/share/gir-1.0']
+  girDirs = [...uniq(dirs), ...girDirs];
 }
 
 module.exports = {
   pretty: false,
   print: false,
   verbose: true,
   environments: ['node'],
-  outdir: '@types',
-  modules: ['Gst-1.0', 'GstWebRTC-1.0'],
+  outdir: 'src/@types',
+  modules: [
+    'Gst-1.0',
+    'GstWebRTC-1.0',
+    'GIRepository-2.0',
+    'NgwNative-0.0',
+  ],
   buildType: 'lib',
   ignore: [],
   girDirectories: girDirs,

src-native/NgwNativeCommon.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#if defined _WIN32 || defined __CYGWIN__
+  #ifdef BUILDING_NGWNATIVE
+    #define NGWNATIVE_PUBLIC __declspec(dllexport)
+  #else
+    #define NGWNATIVE_PUBLIC __declspec(dllimport)
+  #endif
+#else
+  #ifdef BUILDING_NGWNATIVE
+      #define NGWNATIVE_PUBLIC __attribute__ ((visibility ("default")))
+  #else
+      #define NGWNATIVE_PUBLIC
+  #endif
+#endif