fix bug when visiting relative url from root

enforce max header length too
correctly read response header

wrap words instead of char
bump version 0.5.8
don't check tls cert for now

Turns out there are more self-signed sites than otherwise. Apparently
the generally accepted way for gemini is trust-on-first-use. Before I
can implement that properly I'll just turn off cert validation
ctrl-l to jump to address bar
block user interactions during controller callback
more lenient address input
run curio in a separate thread

So that tkinter's mainloop() can take full control of the main thread
and we don't need to repeatedly run the heavy update() method anymore.
more info for pypi
safer arrow characters I guess
more responsive UI, full disclosure
ctrl+a to select all
tell curio we don't need to join()

So it doesn't spam the "task never joined" warning.