Add missing imports for cstdint (#486)

Author: benallard

src/common/ColourPalette.hpp

@@ -20,6 +20,7 @@
 #include <string>
 
 // Include obscure header file for uint32_t definition
+#include <cstdint>
 
 namespace ale {
 

src/common/SoundExporter.hpp

@@ -24,6 +24,7 @@
 
 #include <fstream>
 #include <vector>
+#include <cstdint>
 
 
 namespace ale {

src/emucore/MD5.hxx

@@ -20,6 +20,7 @@
 #define MD5_HXX
 
 #include <string>
+#include <cstdint>
 
 namespace ale {
 namespace stella {

src/emucore/Props.cxx

@@ -21,6 +21,7 @@
 #include <sstream>
 #include <string>
 #include <iostream>
+#include <cstdint>
 
 #include "emucore/Props.hxx"
 

src/emucore/PropsSet.hxx

@@ -19,6 +19,8 @@
 #ifndef PROPERTIES_SET_HXX
 #define PROPERTIES_SET_HXX
 
+#include <cstdint>
+
 namespace ale {
 namespace stella {
 

src/emucore/Sound.hxx

@@ -19,6 +19,8 @@
 #ifndef SOUND_HXX
 #define SOUND_HXX
 
+#include <cstdint>
+
 namespace ale {
 namespace stella {
 

src/emucore/Switches.hxx

@@ -19,6 +19,8 @@
 #ifndef SWITCHES_HXX
 #define SWITCHES_HXX
 
+#include <cstdint>
+
 namespace ale {
 namespace stella {