Support .well-known autodiscovery in the js-sdk (#799)
* Support .well-known autodiscovery in the js-sdk
It's much more useful here than in the react-sdk as it can be reused by more applications. This is also required to make the react-sdk a little easier to manage .well-known lookups as soon it'll be doing it in several places.
Automatic discovery is an abstract concept in the spec and could include more than .well-known in the future, so this is made to be generic enough to support future mechanisms and other resources to discover. There's also a ton of comments (more than normally needed) as people may wish to use this as a reference in their own implementation and it doesn't hurt to explain what everything is doing.
Many of the functions are air lifted from the react-sdk and modified to work within the confines of the js-sdk.
* Swap out uglify-js for uglify-es
So we can start using ES6 dependencies without figuring out how to update babel.
`uglify-es` is compatible with `uglify-js@3` (we were using `@2`) , which is why the same command is used. This commit includes changes to the command line to make the thing run the same as before too.
* Appease the linter
* Appease the linter some more
* Appease the linter: the tiebreaker
* Appease the linter yet again
* Switch to using the already available URL libraries
* Remove excess logging
