Canonical root and recursion

Breaking changes:

• The -r or --recursive option no longer recurses into source maps and source map sources. This lets you set recursion without getting errors for possibly unpublished source map sources

New features:

• A --source-mapoption has been added to enable you to fail on missing source maps or source map sources.
• A --canonicalroot option has been added. This allows hyperlink to resolve a canonical deployment URL as a local one. So https://mntr.dk/opengraph.jpg with a --canonicalroot https://mntr.dk/ would be resolved as /opengraph.jpg when your root is a local file system.

Fixes:

• Added more resilience against servers behaving weirdly when requesting with HEAD-method. A server would respond 502, and also respond 502 on an immediately attempt at recovering with a GET. Added yet another recovery retry on a timeout for this condition