SLY's hotspot compilation is a questionable but seductive idea. At
least make it not generate so much noise.

* sly.el (sly-byte-compile-hotspots): Renamed from
`sly--compile-hotspots'.

* contrib/sly-fontifying-fu.el: Use `sly-byte-compile-hotspots'

* lib/sly-parse.el: Use `sly-byte-compile-hotspots'