Added filtering of duplicate key releases.

src/input.c

@@ -129,6 +129,9 @@ void _glfwInputKey(_GLFWwindow* window, int key, int action, int mods)
     if (key < 0 || key > GLFW_KEY_LAST)
         return;
 
+    if (action == GLFW_RELEASE && window->key[key] == GLFW_RELEASE)
+        return;
+
     if (action == GLFW_PRESS && window->key[key] == GLFW_PRESS)
         repeated = GL_TRUE;