restructure and add ipi texs

ws2019/ipi/uebungen/cpp_headers/newtonwhile.cc

@@ -0,0 +1,15 @@
+#include "fcpp.hh"
+
+double wurzel (double a)
+  {
+      double x=1.0;
+   
+      while (fabs(x*x-a)>1E-12)
+          x = 0.5*(x+a/x);
+      return x;
+  }
+
+int main ()
+{
+  return print(wurzel(2.0));
+}