Increase recycled experience storage.

Also make constants for the unit limits. The experience storage is a separate
value, to be able to change unit limits without breaking savegames.

src/droid.h

@@ -38,7 +38,11 @@
 
 #define DROID_RESISTANCE_FACTOR     30
 
-#define MAX_RECYCLED_DROIDS		32
+#define MAX_MP_DROIDS 450
+#define MAX_SP_DROIDS 100
+#define MAX_SP_AI_DROIDS 999
+// Changing this breaks campaign saves!
+#define MAX_RECYCLED_DROIDS 450
 
 //storage
 extern DROID_TEMPLATE			*apsDroidTemplates[MAX_PLAYERS];

src/structure.cpp

@@ -2562,8 +2562,7 @@ BOOL IsPlayerStructureLimitReached(UDWORD PlayerNumber)
 
 UDWORD getMaxDroids(UDWORD PlayerNumber)
 {
-	return bMultiPlayer? 450 : PlayerNumber == 0? 100 : 999;
-
+	return bMultiPlayer? MAX_MP_DROIDS : PlayerNumber == 0? MAX_SP_DROIDS : MAX_SP_AI_DROIDS;
 }