[enh] start setattr while@else
[mod] refactoring, extract else related stuff to a top class
[mod] continue on setattr while@else
[mod] update todo
[enh] handle simple input with lot of variations for setattr while@else
[enh] same for two lines
[mod] move to_node to Node.from_fst
[doc] update doc about change from to_node to Node.from_fst
[doc] update CHANGELOG
[doc] typo