Commit Briefs
don't let the net process stick around
flush the net ibuf too
flush imsg buffer before quitting
this ensures that all the pending messages, such as the two IMSG_QUIT, but limiting to them, are actually sent. This unbreaks save_session too.
fix certificate mismatch after load_previous_page and proxy
load_previous_page calls directly do_load_url, where the proxy reset happens in load_url.
initialize tabshead and proxylist early
after the re-exec diff, the configuration gets loaded *before* and then the proxy list is initialized. Thus once we start the UI the proxy list is always empty. Solve the headaches by using TAILQ_HEAD_INITIALIZER. Or, in theory we could also avoid the initialization at all, since globals vars should be zeroed.
re-exec the children processes
This way, they get their own new random address space.