ESC]0;stringBEL -- Set icon name and window title to string ESC]1;stringBEL -- Set icon name to string ESC]2;stringBEL -- Set window title to string via https://tldp.org/HOWTO/Xterm-Title-3.html

This is achieved by calling `autosave_hook' in interesting places, like new_tab or free_tab. It'll set up a timer to later persist the session. This is particularly useful to avoid loosing tabs on the event of a crash or unexpected system halt, or other similar event.

URLs like gopher://example.com/1 weren't matched as type 1 before and worse, they weren't really loaded, even thought the spinner started (that's behaviour is from push_button). Now matching of items types is better and a (simple) error page is loaded on unknown types selector.

- don't link gemini' /docs/ and /software/. Link the home page and let the user proceed from there - add a link to the floodgap gopher server

Initially telescope only supported about:* pages and gemini, so it made sense to set TS_VERIFIED on about pages. Now, also various non-tls protocols and TS_UNKNOWN is used more, so is more coherent to use it also for about pages.