bake: Optimize cache handling for the baking process. - Get rid of the 2-level pipeline runs... handle a single set of passes. - Go back to load/render segments/layout passes for pages. - Add descriptions of what each job batch does. - Improve the taxonomy pipeline so it doesn't re-bake terms that don't need to be re-baked. - Simplify some of the code.

---
config:
    site:
        root: /~john/public/
in:
    pages/about.html: 'URL: {{page.url}}, LINK: {{pcurl("missing")}}'
    pages/_index.html: 'URL: {{page.url}}'
outfiles:
    about.html: 'URL: /%7Ejohn/public/about.html, LINK: /%7Ejohn/public/missing.html'
    index.html: 'URL: /%7Ejohn/public/'