remove 'name' arg from file_exists docstring

Env variables for server root & URL in terminals

Only path is used, not separate name, path.

This came up on reddit: if you want to open a notebook or a file in the
text editor from the terminal inside the notebook web interface, you can
construct a URL to open. But to do that accurately, you need to know the
root directory where the server is looking, and the first part of the
URL. This exposes both of those as environment variables:
$JUPYTER_SERVER_ROOT and $JUPYTER_SERVER_URL.

Store frontend config in nbconfig/ subdirectory

Closes gh-211

Don't uglify js

ipykernel no longer has requirements.txt

Rough draft of documentation for the notebook REST API for kernels, kernel specs, and sessions

fix url for custom.css

Revert custom themes

The customizable themes were not actually ready for merge.

sort order of all files and directories is now case-insensitive

Use default theme

step-forward button

served from .jupyter/custom

Add less config for themes and apply throughout

Display HTML in pager if supplied

include version in --version output

It seems to cause problems, and we care a lot more about request count than minimizing bytes.

This is still an interim measure until the generic 'put a mimebundle on
the page' machinery can easily be used here.

Fix front-end extension loading

    
protects agains CSRF on POST endpoints via forms.

updated keyboard.js to throw errors instead of strings.

Properly render newlines etc. in raw_input() prompt

Also do not explicitly set monospace font in raw_container_input,
because that the container's width to be inconsistent with the (later)
output div's width.

Also, the input tag becomes a child of the pre tag.