Update paramiko/file.py

Added a closed property as an alternative accessor to BufferedFile's _closed property.
Make send() and recv() fail when channel is closed

``sendall()`` was checking if the channel has been closed, 
and failed accordingly, but ``send()`` and ``recv()`` did not.
This meant that ``chan.send("foo")`` when the channel was already
closed, just blocked forever.
Forgot to import errno
Git ignore built docs dir
Git ignore built docs dir
Git ignore built docs dir
Make docs target build whenever Paramiko files change
Bump dev version to 1.10
Fix #113: add timeout passthru to exec_command
Make docs target build whenever Paramiko files change
Merge branch '1.8' into 1.9
Merge branch '1.9'
Fix #94
Merge pull request #95 from Bockit/master

Add a closed property to BufferedFile
Changelog re #80, fixes #80
Merge pull request #99 from tomerfiliba/patch-1

Make send() and recv() fail when channel is closed
Make send() and recv() fail when channel is closed

``sendall()`` was checking if the channel has been closed,
and failed accordingly, but ``send()`` and ``recv()`` did not.
This meant that ``chan.send("foo")`` when the channel was already
closed, just blocked forever.
Forgot to import errno
Make send() and recv() fail when channel is closed

``sendall()`` was checking if the channel has been closed,
and failed accordingly, but ``send()`` and ``recv()`` did not.
This meant that ``chan.send("foo")`` when the channel was already
closed, just blocked forever.
Forgot to import errno