implement persistent tab history The session file is now overloaded with the history info, that means that upon startup telescope can repopulate each tab history! The price to pay is that one can't start an old telescope with a new session file, otherwise will get a lot of fancy '<' and '>' tabs...

simplify the lazy tabs handling it's cleaner to just toggle the lazy bit in switch_to_tab instead of pushing that complexity in load_url. While there also try to simplify the function and its documentation from unnecessary checks and extra verbosity. This also fixes a bug where Telescope ended up pushing the url on the history *twice* at startup.

reuse struct session_tab when saving the session

move parse_last_session to the fs process ~/.telescope/session was parsed in the main process before dropping in the sandbox: that's no good. This moves the initialization of the ui events later in ui_main_loop and makes so that the fs process, after entering the sandbox, parses and sends the content of the last session back to the main process; when it's done the ui gets loaded and telescope is back rocking. I'm plannig to re-use the struct session_tab during the save session operation soon.

switch to our new struct download for the downloads

fix build, missing include on fs.h

add a safe/sandbox mode When enabled with the -S (or --safe) flag, prevent telescope from writing files to the disk.

kill extra empty line

fmt (some missing space -> tab conversion)

schedule ui redraw on tab new/free this helps to correctly manage the tab bar when tab-bar-show is 1.

move more stuff outta telescope.c