Drop 2.6 and 3.2 from Travis tests
Remove extra assert methods needed for Python 2.6
Update docs for Python version support
Drop nested() function for context managers
Remove _total_seconds helper function
Remove Python 2.6 workaround
remove workaround for 2.6 support
Fix IPython.start_kernel()

Closes gh-4005
Fix passing user_ns to IPython.start_ipython()
Fix passing user_ns to IPython.start_kernel()
irunner use python -m IPython to launch subprocess with matching interpreter

Closes gh-4013
Use traitlet on InteractiveShellApp instead of storing user_ns via __init__
Add REPL-like printing to %%R cell magic
Fix warning when running IPython.kernel tests

The signature of TemporaryDirectory.cleanup() changed just before Python 3.2, and our
TemporaryWorkingDirectory subclass was receiving an unexpected parameter. This copies
in a newer TemporaryDirectory.cleanup() implementation for Python 2.7.
Use onlyif_unicode_paths in utils tests
Refine unicode tests for ultratb
Skip some more tests that require unicode paths
made docstrings clearer and more explicit/correct for eval and R methods
Use print_function in IPython.utils.tempdir
moved printing logic to the R magic function (out of the eval function)