Don't catch unhandled exceptions in examples.

Let Python handle printing a traceback and exiting in these cases.
Allow importing when sys.stdout is reassigned on Python 3

Closes gh-30
Correct handle when select in spawn returns with an error (e.g. SIGWINCH)
ExceptionPexpect.__init__: invoke super's init

This avoids an exception in the following:

        import pexpect
        import pickle
        pickle.loads(pickle.dumps(pexpect.EOF('hey you')))
Merge pull request #33 from aho-iridium/master

Correctly handle when select in spawn returns with an error (e.g. SIGWINCH...
Test for previous commit
Merge pull request #34 from offby1/master

ExceptionPexpect.__init__: invoke super's init
Merge pull request #31 from takluyver/stdout-bytes-py3

Allow importing when sys.stdout is reassigned on Python 3
Merge pull request #29 from takluyver/examples-main-blocks

Don't catch unhandled exceptions in examples.
Squash some Sphinx warnings
Prepare for 3.1 release
Fix documentation of using auto_prompt_reset.

Closes gh-35
Make code style more regular
Polish pxssh docstrings
Document force_password attribute
Update pxssh example for Python 3
Merge pull request #36 from takluyver/pxssh-docs

Pxssh docs
Fixing issue where errno does not exist on select.error
Simplifying code to use format of select.error arguments that works in both Py27 and Py3
Adding test to for signal handling error