Bug fix - task now builds on Arch Linux

- Applied patch to allow task to build on Arch Linux (thanks to
  Johan Friis).

src/Date.h

@@ -27,6 +27,7 @@
 #ifndef INCLUDED_DATE
 #define INCLUDED_DATE
 
+#include <stdio.h>
 #include <string>
 
 class Date;

src/Grid.h

@@ -27,6 +27,7 @@
 #ifndef INCLUDED_GRID
 #define INCLUDED_GRID
 
+#include <stdio.h>
 #include <string>
 #include <vector>