Like previously did with the session file, now the main process doesn't parse anything with the only exception being the configuration file. With this in, the only bit from fs.h still used in the main process is the path to the configuration file.

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...

~/.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.

and while there also publish various path. It's easier and better to have all of them exported from here instead of hardcoding them in other files (such as sandbox.c)

Use XDG-compliant paths unless ~/.telescope already exists. Provide a script to migrate to XDG-style directory for users who wish to do so.