add the library I created for handling the management of dynamic text-documents(documents that are edited by an arbitrary count of different instances at a time). It is nearly ready, it is possible to selectively undo any single edit made by any instance(as long as there is no conflicts). This will allow an undo-function for each single user of the file-collaboration, also the server might undo changes made by a special user and kick him. Also(and especially) the system helps putting together edits made to different versions of a document consistently. Maybe the system could also be used for local edit-history some time.