shelve: rename method for data write/read There are no user of this code nor any code related to obsshelve in the extensions right now, so we rename the function before using them. Note: The shelvedfile looks a bit strange. We should probably refactor it, however, this is an adventure for another series.

shelve: move createcmd next to _docreatecmd It is simpler not to have to jump around the file all the time.