replace bin2num() with unpack()

docs/ackermann.rst

@@ -37,7 +37,7 @@ nCrypt has devised a way to calculate the value of the Ackermann function using
             loop (14) {
                 if (length(stk) > 0) {
                     bytes top = stk[0:1];
-                    m = bin2num(top);
+                    m = unpack(top);
 
                     // pop
                     stk = stk[1:length(stk)];

docs/functions.rst

@@ -93,10 +93,6 @@ bytes Operations
 
   Converts a number ``num`` into a byte array of certain size ``size``, including the sign bit. It fails if the number cannot be accommodated.
 
-* ``int bin2num(bytes b)``
-
-  Converts a bytes array ``b`` to an integer, including minimal encoding in signed magnitude format. 
-
 * ``int length(bytes b)``
 
   Returns the length of ``b``.

docs/rabin.rst

@@ -35,7 +35,7 @@ Rabin Signature
         public function verifySig(int S, bytes U, bytes m, int lambda, bytes n) {
             require(hash160(n) == this.nHash);
 
-            int h = bin2num(this.hash3072(m ++ U));
-            require(S * S == h + lambda * bin2num(n));
+            int h = unpack(this.hash3072(m ++ U));
+            require(S * S == h + lambda * unpack(n));
         }
     }

docs/rpuzzle.rst

@@ -19,7 +19,7 @@ One crucial step in R-Puzzle is to extract ``r`` from `DER`_ encoded signature.
 
         function getSigR(Sig sig) returns (bytes) {
             bytes lenBytes = sig[3:4];
-            int len = bin2num(lenBytes);
+            int len = unpack(lenBytes);
             bytes r = sig[4:4+len];
             return r;
         }