Readline's ChangeLog.Cygnus files

[Elena Zannoni]

I think these files just shouldn't be there under such names.

./readline/ChangeLog.Cygnus
./readline/doc/ChangeLog
./readline/examples/ChangeLog.Cygnus

Since readline doesn't use the ChangeLog files, but one CHANGELOG file
instead, we could just call them ChangeLog, but that could be confusing
if readline decides to start using ChageLogs.
Any preferences?
ChangeLog.local?
ChangeLog.gdb?

Elena