BREAKING: refacto removed all buffer thing, instead one should use the more generic and flexible 'span' ; bufferBranches is replaced by spanBranches, and it's nested inside a regular branch ; it's now possible to continue a span, restart it, force expand it (even if there is a missing part), and copy it to another one ; return is refactored, it is an object (or true) with optional properties matchState, matchMicroState and errorAction (former returnErrorAction) ; XML highlighter refined