Make fontkit cross-platform compatible again

[Pomax]

Closes #118

This makes everything node-runnable again, obviating the need for OS-presupplied utilities. It adds npm-run-all as a script running convenience, and it adds shx as cross-platform utility runner for common unix utils such as cp and rm. Finally, it also adds cross-env to ensure that environment variables are set in a way that work in unix, linux, OSX, and Windows alike.

npm test shows all tests passing, with the same coverage.

[Pomax]

@devongovett probably worth landing, to unblock Windows users (either by choice or because work demands it) since CI says it's all good =)

[devongovett]

Not sure how I feel about this. Doesn't Windows have bash now? What about cygwin?

Admittedly my knowledge of windows is very limited, but Make is a tool that's designed exactly for this purpose. npm scripts are not.

[Pomax]

This is exactly what npm scripts were designed for, too, and have the benefit of actually working on Windows, whereas make simply doesn't (unless you make people jump through painful hoops).

That said, the Linux Subsystem is still in beta, so you can't really rely on it. Cygwin is massively huge, and for node projects there isn't a single thing in Cygwin that isn't already covered by node/npm packages that have clean CLI invocations. There is literally no reason to have any kind of reliance on make and Makefile if you're writing a node project =)

This PR simply ports the instructions you had in the Makefile to a form that fits "the proper node way" of bootstrapping and using CLI-based task running without baking in anything that's platform specific and prevents the project from running on one or more operating systems.

[davelab6]

(I agree with Mike :)

[Pomax]

hm. bump?

[Pomax]

bump, again? =)

[Pomax]

rerebump =)

(feel free to close it, but it would still benefit loads of people to merge this without any change in build funcationality)

[Pomax]

@devongovett this is still very much worth landing

If you no longer really work on fontkit, could I selfishly ask you just hit merge so that people who do still use it a lot in the font work can use this normally on windows, without affecting anyone on nx operating systems? It doesn't get in your or anyone else's way, but does make life much easier for an estimated 50% of the developer community.

[davelab6]

Thank you Devon!!

[devongovett]

Yeah sorry guys, I've been busy with other projects lately. Today I made an org https://github.com/foliojs and I'll be moving fontkit, textkit, pdfkit, and all related dependencies across the whole stack there so more contributors can be involved with reviewing and merging code. @diegomura of react-pdf is already helping out a bit, and I hope to bring others on as maintainers as well. Hopefully that will help with the long term support for these projects.

[Pomax]

That's great to hear!