Put the parameter watchexp back in (changed watchexp from an int
to a bool).  Also second argument to watchexp is now converted
to Decimal, just as with all the other two-argument operations.

Thanks Mark Dickinson.
diff --git a/Lib/decimal.py b/Lib/decimal.py
index 8543e10..b2bfc56 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -2160,12 +2160,13 @@
             end -= 1
         return Decimal( (dup._sign, dup._int[:end], exp) )
 
-
-    def quantize(self, exp, rounding=None, context=None):
+    def quantize(self, exp, rounding=None, context=None, watchexp=True):
         """Quantize self so its exponent is the same as that of exp.
 
         Similar to self._rescale(exp._exp) but with error checking.
         """
+        exp = _convert_other(exp, raiseit=True)
+
         if context is None:
             context = getcontext()
         if rounding is None:
@@ -2182,6 +2183,16 @@
                 return context._raise_error(InvalidOperation,
                                         'quantize with one INF')
 
+        # if we're not watching exponents, do a simple rescale
+        if not watchexp:
+            ans = self._rescale(exp._exp, rounding)
+            # raise Inexact and Rounded where appropriate
+            if ans._exp > self._exp:
+                context._raise_error(Rounded)
+                if ans != self:
+                    context._raise_error(Inexact)
+            return ans
+
         # exp._exp should be between Etiny and Emax
         if not (context.Etiny() <= exp._exp <= context.Emax):
             return context._raise_error(InvalidOperation,