Regression caused by the upgrade to Webpacker 6.0 in 90cd3293e. This
caused various Javascript errors in old versions of Chrome, which
somehow resulted in the keyboard shortcut for visiting the next page
being triggered when you pressed any key.
Specifically, the mobx library (used by the TagCounter component) called
`Object.entries`, which isn't available in Chrome 49, and for some
unknown reason this triggered the buggy shortcut behavior.
`Object.entries` is supposed to be automatically polyfilled by Babel to
support old browsers, but something changed in Webpacker 6 that broke
this and I couldn't get it working again. The probable cause is that
Webpacker 6 no longer transpiles code inside ./node_modules by default,
which means that any libraries we use that use new Javascript features
won't get transpiled down to support old browsers, but even after fixing
that it still didn't work. The workaround is to just drop mobx and
preact entirely to avoid the issue.
Rewrite the tag counter widget (the one above the tag edit box) to use
React. This is a trial run for using React elsewhere.
We actually use Preact instead of React because it's lighter weight.
We use Mobx for state management because it's cleaner than React's
setState or useState.
This incidentally fixes a couple bugs:
* The tag counter wasn't updated when deleting tags with backspace
* The tag counter wasn't updated when pasting in new tags.
This was only used on the saved search index. It let you click on column
headers to sort the table by that column. This doesn't make sense now
that saved searches are paginated.
Add the following fonts:
* Comic (Comic Relief)
* Slab Sans (Anton)
* Slab Serif (Rokkitt)
* Formal Serif (Lora)
* Formal Cursive (Petit Formal Script)
* Print (Kalam)
* Hand (Indie Flower)
* Narrow (Archivo Narrow)
* Blackletter (Unifraktur Maguntia)
Add the following font aliases:
* Comic Sans MS is aliased to Comic Relief.
* Arial Narrow is aliased to Archivo Narrow.
* Rockwell is aliased to Rokkitt.
* Impact is aliased to Anton.
Very old browsers (in particular, Firefox 16 and iOS 8.4 Safari) don't
support flexbox without prefixes, which breaks sidebar and comment
layouts. Extend the browserlist config so that autoprefixer generates
flexbox prefixes for these browsers.
