Support nesting with cause

[conartist6]

I'm building an application which really needs nested errors. The fs can throw, but in my application just seeing what failed isn't enough to understand what action was being attempted when a failure occurred. Instead I must catch the source error, attach some additional context, and rethrow.

I'd like to be able to attach the original error as a cause. Spec-level support for this is already underway. A shim has been published as well, but while it can get a cause property set up correctly, it doesn't contain any logic about rendering causes. This library has an opportunity to be the first to present such information in a useful way and kickstart the community's ability to use this feature.

I'm going to make a fork and see what I can do.

[conartist6]

The only slight problem is that my personal temptation is to hard fork it as I don't know coffeescript and I don't want to.

[AriaMinaei]

Supporting cause sounds like a good idea!

As to coffeescript, I'll be happy to merge back TS or ESNext :)