<up> and <down> are now bound to previous/next-completion instead of previous/next-history-item

* cmd.c (cmd_previous_completion): add previous-completion (cmd_next_completion): add next-completion (cmd_insert_current_candidate): add insert-current-candidate * minibuffer.c (enter_minibuffer): support completions in minibuffer

restore the current line, so the editing operations can actually modify the input buffer, instead of the history string.

load_previous_page calls directly do_load_url, where the proxy reset happens in load_url.

and while there document some missing keys.

This way, they get their own new random address space.

This would leave the last column white if !olivetti-mode and a background color for some body lines

empty lines inside pre blocks were misleadingly matched as LINE_TEXT.

Don't crash when there's a certificate mismatch and after saving the cert, before choosing to persist it, the page gets redirected; also, don't repeat the "Certificate mismatch" after the first yes, if there's a redirect. Now when the user accept a certificate, is treated as temporary saved for the whole session.