add notes on the copied pylib version

CHANGELOG

@@ -15,6 +15,10 @@ UNRELEASED
   correctly also on python2 and with pytest-xdist runs. (the fix
   requires py-1.4.20)
 
+- copy, cleanup and integrate py.io capture
+  from pylib 1.4.20.dev2 (rev 13d9af95547e)
+
+
 2.5.1
 -----------------------------------
 

_pytest/capture.py

@@ -2,6 +2,8 @@
     per-test stdout/stderr capturing mechanisms,
     ``capsys`` and ``capfd`` function arguments.
 """
+# note: py.io capture was where copied from
+# pylib 1.4.20.dev2 (rev 13d9af95547e)
 import sys
 import os
 import tempfile

testing/test_capture.py

@@ -1,3 +1,5 @@
+# note: py.io capture tests where copied from
+# pylib 1.4.20.dev2 (rev 13d9af95547e)
 from __future__ import with_statement
 import os
 import sys