CMake: Build the webextensions plugin

src/gtk/webview_webkit2.cpp

@@ -407,13 +407,14 @@ wxgtk_initialize_web_extensions(WebKitWebContext *context,
     GVariant *user_data = g_variant_new("(s)", address);
 
     // The first value is the location in which the extension is supposed to be
-    // normally installed, while the other two are used as fallbacks to allow
+    // normally installed, while the other three are used as fallbacks to allow
     // running the tests and sample using wxWebView before installing it.
     const char* const directories[] =
     {
         WX_WEB_EXTENSIONS_DIRECTORY,
         "..",
         "../..",
+        "lib",
     };
 
     const char* dir = NULL;