add completions for Node.js & NPM
Add support for toor account.

Currently fish doesn't recognize toor as special. However, it's likely
that on BSD systems, fish shell will be used on toor, not on root (toor
is an intentionally existing account to use more advanced shell on, like
shell).
Parse OSC codes in escape_code_length(). They begin with <esc> ] and are terminated with ST (<esc> backslash) or BEL (ASCII 7).
Fix up OSC / iTerm2 escape code parsing as part of #1565