[tools] Improve error handling.
[lib] Pass through options to network requests.

- Add options to API calls that eventually make network requests.
- Done to allow passing options such as strictSSL to low-level requests.
- Use common function for getting authority config URLs.
[tools] Config and request updates.

- Add function to write out configs.
- Add config and authority help.
- Add config read options for strict mode.
- Move exported config functions into config object.
- Export function to create common request options.
  - Needed to get strictSSL command line option easily.
- Fix bugs.
[tools] Add function to create IDs.

- Common function to create a URL from a base URL and an input which can
  be nothing, a full URL, or short URL using the base URL.
[tools] Add access key registration tool.

- Key registration:
  - Port of examples/register-new-key.js.
  - Usage: "./bin/payswarm keys -r" with various options.
- Small refactorings for new makeId and other features.