Review splitter functionality cause of bug fixing

Splitter face code have some documents related problems. I've considered a refactor but for now there are many dependencies involved and I'm not completely sure if this is the way to go. I will have to decide with bxtrx if is right or not. This refactor should reduce the dependencies between the splitter and the document. Based at least on the skills gained today about how works the splitter implementation, will simplify for me the debugging experience for tomorrow when the refactor may introduce new bugs.