[mod] let's record what kind of key I'm adding
[enh] add a way to convert back node to fst
[enh] add a way to convert back a RedBaron instance insto fst
[enh] do magic __repr__
[enh] add the help() method
[mod] extract list behavior of RedBaron into a NodeList topclass
[enh] use this NodeList on everylist
[mod] __fst__ -> fst
[mod] change help() behavior
[enh] make help() display better
[enh] better .help() on NodeList
[fix] actually use NodeList on ... list of nodes
[mod] remove useless import