improvement for SD-491: text items creator

Added the list of creators to the text items. One can see now the original creator of the item and the list of all creators who ever made changes to the item. Also the number of the modified version is available with the corresponding creator.
So from what I understand we are happy with the version we already have merged? At the moment we have "original_creator" who is the one who created the story, and each time when the item is modified we have the corresponding "creator".Should I change the name into version_creator and let the implementation as it is?