fixed issue 1862, readline problem in cpdb, thanks kmelevskiy

VERSION

@@ -1 +1 @@
-Version 2.8.2-stable+timestamp.2014.01.27.15.49.57
+Version 2.8.2-stable+timestamp.2014.01.30.08.43.19

scripts/cpdb.py

@@ -10,6 +10,9 @@ from collections import deque
 import math
 import re
 import cmd
+try:
+  import pyreadline as readline
+except ImportError:
   import readline
 try:
     from gluon import DAL