Icon is only visible if content is available for the editor in question.
Split editor settings into two groups - one is persistent settings and one is progress/state.
Tutorials record their dismissed state, so users can permenantly disable the 'nag' for a particular tutorial.
Tutorial content now solidifies when the mouse is hovered over it, so it can be made easier to read.
Fixed crash on startup if an intro tutorial was displaying rich text.
Also fixed crash for TTP# 345094, where a zero-length tutorial was being accessed.
[CL 2275934 by Thomas Sarkanen in Main branch]
