Allow JR between sections

Previously, JR was only allowed if the destination label was in the same
section as the JR. This patch removes this restriction. The check to see
if the relative value overflows is now done when linking the ROM.

Signed-off-by: Antonio Niño Díaz <[email protected]>

docs/rgbds.5.html

@@ -121,6 +121,7 @@ REPT NumberOfSections
             BYTE    Type         ; 0 = BYTE patch. 
                                  ; 1 = little endian WORD patch. 
                                  ; 2 = little endian LONG patch. 
+                                 ; 3 = JR offset value BYTE patch. 
  
             LONG    RPNSize      ; Size of the buffer with the RPN. 
                                  ; expression.