[Bug-readline] vi-mode remapping

[A Higgs]

There are some undocumented limitations to remapping keys in vi-mode.
The vi-char-search is probably known because the same function is used
for several different keys. But it is also the case that a remapped
'vi-next-word' works with 'vi-delete-to' (standard or remapped)
whereas a remapped 'vi-end-word' does not work with 'vi-delete-to'
(standard or remapped). Is this a bug, or is the case that a remapped
'vi-next-word' works with 'vi-delete-to' is an accident?

And regardless of the bug-status of these issues, what is the
likelihood that someone with little experience with C (or any such
language) would be able to modify the source and hard-code desired
mappings? Thank you.