When a notebook is written to file, name the metadata name u''.
notebook supports raw_input and %debug now

updates Frontend-Kernel model example notebook to reflect this.

closes #3489
add 'No Checkpoints' to Revert menu

when there are None, rather than an empty menu.

closes #3261
update CodeMirror component to 3.14

I believe this closes #3361, if @fperez and/or @fonnesbeck can confirm.
use `isoformat()` in jsonutil

allows preservation of timezone info.

Timezone info is still ignored in the extract-dates part, for now.
add IPython.utils.tz

Basic support for tz-aware UTC methods on date time objects.

The raw `utcfoo` methods still produce naïve objects,
so they are wrapped in a simple zero-offset tz-aware object.

This allows jsonutil to publish the timezone info,
eliminating the ambiguity of naïve timestamps (Firefox assumes local time, WebKit UTC).
add timezone info to `last_modified` in notebook managers

now Firefox won't get confused, turning utc timestamps into local times.

closes #3396
allow just the trailing Z for timezone
ensure 'default' is first in cluster profile list

when sorting, `'default'` is transformed to `''`.
tweak regexp handling of tzinfo

allows for excluding the 'Z' from the timezone info
test jsonutil handling of dates
cleanup stale, unused exceptions in parallel.error

closes #2044
ensure raw_input returns str in zmq shell

matches raw_input.  Some things can't handle unicode objects (e.g. `help()`).

closes #1145
Use a CDN to get reveal.js library.
remove debug statement

and anchor
Don't hardcode posix paths in nbconvert

use `os.path` for building paths

closes #3534
allow cython cache dir to be deleted

workaround by clearing the distutils mkpath cache,
which prevents it from ever creating a given path more than once.

closes #3010
respect image size metadata in qtconsole

This doesn't mean retina support, as image data is actually resampled, unlike in a browser.
use smooth transform in QtConsole
Make configurable the url where look for reveal.js library.