* use content-hashed paths for static resources (except the top-level
request), with immutable Cache-Control headers. This should improve
cache behavior in both directions: avoid preventable HTTP requests and
cause immediate refresh when needed. I had some staleness when
browsing with my phone.
* set up the favicons properly while I'm at it (closes#50). I used the
convenient favicons-webpack-plugin to build everything from a .svg.
I've hit an error similar to lovell/sharp#1593 at least once though so
I might change my mind about that part if it continues to be
problematic.
* use http-serve's new directory traversal code for static file serving.
This removes the odd behavior where files that weren't present at
server startup couldn't be served. (I wasn't comfortable switching to
the content-hashed paths before doing this.) It also means the static
files can be served compressed. JSON API responses were already served
compressed, so this closes#25.
* for a given API URL, decide if we want it to be cached or not
server-side. Stop using jQuery's kludgy cache-defeating _=<timestamp>
URL parameter. I might start setting etags on some of these things
and could serve 304 Not Modified responses if it's genuinely
unmodified.
