Use partialCached to avoid any perf penalty.
TODO: limit the scope I pass to them.
I noticed a teeny tiny perf improvement after doing this, probably
because now some giant data structures only need to be generated once.
- Fix use of shortcodes in some pages so authorship is parsed correctly
- Explicitly show author for each entry in a data feed, so parsers don't
get confused by reply-authors.
Link targets need to be focusable to work with VoiceOver.
Making <main> focusable causes some side-effects, like making the TAB
key go to the beginning of <main> instead of the element after the
currently-clicked region.
Also removes the annoying outline around "main" in some non-mainstream
browsers, without having to add extra CSS.
