slight change to ADT repr

Recurse into tuple args when printing. This looks better
especially for empty tuples, which show up a lot as
clauses in If statements.

Author: percontation

adt.py

@@ -69,6 +69,8 @@ def qstr(x):
                 return '0x{0:x}'.format(x)
             elif isinstance(x, ADT):
                 return str(x)
+            elif isinstance(x, tuple):
+                return "(" + ", ".join(qstr(i) for i in x) + ")"
             else:
                 return '"{0}"'.format(x)
         def args():