* fix: update to latest sapper
fixes#416
* fix error and debug pages
* requestIdleCallback makes column switching feel way nicer than double rAF
* add export feature
* add better csp info
* workaround for sapper sub-page issue
* clarify in readme about exporting
* fix now config
* switch from rIC to triple raf
* style-loader is no longer used
* update theming guide
Based on issues I'm seeing on iOS Safari, I'm guessing that my IDB caching is too aggressive and is hitting origin storage limits, which causes IDB transactions in safari to fail silently and never call any transaction callbacks (`onblocked`, `onerror`, `oncomplete`).
This is pretty bad and causes Pinafore to basically just not work unless you clear site data, which we should avoid. 2 weeks was probably unnecessary anyway; in a social network, who cares about content that's 2 weeks old?
