float.h needed for FLOAT_MAX used in this file

Index: game/Entity.cpp
--- game/Entity.cpp.orig
+++ game/Entity.cpp
@@ -32,6 +32,7 @@
 #include "Inventory/Cursor.h"
 #include "AbsenceMarker.h"
 #include "Objectives/MissionData.h"
+#include <float.h>
 
 /*
 ===============================================================================
