Unify output : characters. Fixes #692 (#693)

Author: utkonos

pyflakes/messages.py

@@ -13,8 +13,8 @@ def __init__(self, filename, loc):
         self.col = getattr(loc, 'col_offset', 0)
 
     def __str__(self):
-        return '%s:%s:%s %s' % (self.filename, self.lineno, self.col+1,
-                                self.message % self.message_args)
+        return '%s:%s:%s: %s' % (self.filename, self.lineno, self.col+1,
+                                 self.message % self.message_args)
 
 
 class UnusedImport(Message):