restructure and add ipi texs

ws2019/ipi/uebungen/cpp_headers/UseQueueSTL.cc

@@ -0,0 +1,13 @@
+#include<queue>
+#include<iostream>
+
+int main () {
+  std::queue<int> q;
+  for (int i=1; i<=5; i++)
+    q.push(i);
+    
+  while (!q.empty()) {
+    std::cout << q.front() << std::endl;
+    q.pop();
+  }
+}