Merge pull request #11 from minrk/widgets

Widget review
Removed blame comment
Simplify get_msg_cell function of notebook.js
Renamed widgets...

TextWidget, TextareaWidget, CheckboxWidget, and SelectWidget
Fixed Accordion test broken by last commit
Merge pull request #4374 from jdfreder/widget-msg

IPEP 23: Backbone.js Widgets
don't use `python -m package` on Windows Python 2

because it doesn't work due to bizarre hacks in multiprocessing.
sort dictionary keys before comparison, ordering is not guaranteed
Merge pull request #4909 from juliantaylor/py3-testfix

sort dictionary keys before comparison, ordering is not guaranteed
Merge pull request #4911 from minrk/windows-is-the-worst

Don't use `python -m package` on Windows Python 2
Merge pull request #4908 from minrk/oinspect-builtin-docstrings

detect builtin docstrings in oinspect
remove accidentally committed print statement
add notebook signing to nbformat
sign notebooks
add nbformat.sign.NotebookNotary
add `ipython notebook trust` subcommand
use configured scheme, not stored scheme when checking signatures

protects against notebook author choosing bad hash scheme.
Notaries sign notebooks now
move `ipython notebook trust` to `ipython trust`

and move App definition to nbformat.sign (maybe it should get its own file).
tweak default profile_dir

needed for testing