Add a Swap Buffer node, giving you an infinite number of string variables

- Also fix the string buffer so that it actually works.
- Also add a node to change the text of a sign

rsrc/strings/specials-opcodes.txt

@@ -43,8 +43,8 @@ append-ter
 pause
 start-talk
 quest
-
-
+swap-buf
+sign-buf
 
 
 once-give-item

rsrc/strings/specials-text-general.txt

@@ -734,6 +734,38 @@ Unused
 Unused
 Special to Jump To
 --------------------
+Swap String Buffer
+Unused
+Unused
+First part of message
+Second part of message
+Unused
+Unused
+Unused
+Which string buffer?
+Unused
+Unused
+Unused
+Unused
+Unused
+Special to Jump To
+--------------------
+Alter Sign Text
+Unused
+Unused
+First part of message
+Second part of message
+Unused
+Unused
+Unused
+Which sign?
+Unused
+Unused
+Unused
+Unused
+Unused
+Special to Jump To
+--------------------
 Special Name
 sdf1
 sdf2