rm ihaskell-display/ihaskell-*/stack.yaml

Andrew Gibiansky created all these package stack.yamls with this commit:

> commit f9846b6b
> Author: Andrew Gibiansky <andrew.gibiansky@gmail.com>
> Date:   Tue Jun 7 17:26:47 2016 -0700
>
>     Separate stack.yaml for each package for simplicity

The resolvers for all these stack yamls originally agreed with the
root stack.yaml, but now they're way off, apparently out of neglect.
Let's just delete them.

Fix compliance with Jupyter 5.0 spec for idle messages

jrg/with anim fps

Passthru of some release internal expressions

This is so that these can be reused (e.g.: for
specifying a nixos jupyter service kernel).

labextension npm dependency bounds loosen

Relax upper version bounds on the jupyterlab alpha dependencies
for ihaskell_labextension. It looks to me like these version bounds
were intended to allow the entire major alpha 0.*.* version range, but
the the prefix caret only includes minor versions if the major version
is 0.

Let's set the upper bound to 2.0.0, because according to SemVer, that
is the next version number which we would expect to have breaking
changes.

Attempt to set error status

Change extend to override in release.nix

Make unique labels using a timestamp for svg elements.

This reverts commit 96fe2ef5, reversing
changes made to e373bd3d.