updated for version 7.3.903
Problem:    Crash on exit writing viminfo. (Ron Aaron)
Solution:   Check for the history to be empty.
Added tag v7-3-903 for changeset 166b3df562ea
updated for version 7.3.904
Problem:    Using memory freed by the garbage collector.
Solution:   Mark items in aucmd_win as used.
Added tag v7-3-904 for changeset bdab73bf24a8