Merge unity:gcc-72-errors into unity:master

[Marco Trevisan (Treviño)]

Fix gcc 7.2 build errors

diff --git a/UnityCore/GLibSource.h b/UnityCore/GLibSource.h
index 061fa2b..6994dc3 100644
--- a/UnityCore/GLibSource.h
+++ b/UnityCore/GLibSource.h
@@ -25,6 +25,7 @@
 #include <glib.h>
 #include <memory>
 #include <unordered_map>
+#include <functional>
 
 namespace unity
 {
diff --git a/unity-shared/IconLoader.h b/unity-shared/IconLoader.h
index fb4587e..81041a6 100644
--- a/unity-shared/IconLoader.h
+++ b/unity-shared/IconLoader.h
@@ -23,6 +23,7 @@
 #include <boost/utility.hpp>
 
 #include <memory>
+#include <functional>
 #include <gtk/gtk.h>
 #include <UnityCore/ActionHandle.h>
 #include <UnityCore/GLibWrapper.h>