Add API function to install a kernelspec
Add kernelspec command line entry point
Fix applications displaying subcommands
Add test for installing kernel spec
Trim which options are exposed on kernelspec CLI
Create REST API for kernel specs
Test kernel specs REST API

And fix kernel not found producing a 404 code.
Refactor kernelspec resource handler to separate URL prefix
Put full kernel info in REST API response for all kernels
Deterministic sort for kernelspec list, better error for install
Also look in /usr/local/share/ipython/kernels
Move strip_ansi function to utils
Require jsonschema for nbformat, html and nbconvert tests
Skip some tests if nbformat not importable

Closes gh-5970
nbformat also requires jsonpointer
Add jsonschema & jsonpointer requirements for JS tests
Fix bootstrap location in package_data
Merge pull request #5971 from takluyver/jsonschema-test-dep

Allow tests to run without jsonschema
Wait for keyboard help fadein and fadeout.
Use waits instead of sleeps.