rpn list: changed to standard list

added alias for rpm item pointer standard list
renamed alias for rpm item pointer standard vector
added constant iterator access functions for being and end of list
removed at access function (standard lists cannot be access by index)
changed insert index argument to iterator argument
added new append iterator function (returns iterator of item appended)
changed detection of first time through loop in text function

changed regular for loops to range-for loops for iterating over items
  (auto not used so that Qt Creator completion still works)
updated translator output access functions
  (insert and new append iterator)
changed input command translate to use list iterator instead of index