Remove deprecated XML-RPC Interface
Remove deprecated XML-RPC Interface

It has been unmaintained for ages. Also:

- the current version of the phpxmlrpc library [[1]] is now at a new
  major version, and has a different api
- it does not make too much sense to distribute toxmlrpc.inc.php without
  requiring/distributing phpxmlrpc.inc as well
- for those interested in using adodb as part of xmlrpc servers, or even
  as a full-fledged proxy driver (similar to the built-in rest proxy
  one) it might be easier to download the phpxmlrpc/extras package,
  which has been dormant for a while but is getting refreshed these
  days. I might even externalize the adodb-phpxmlrpc bridge to its own
  standalone package :-)

Fixes #671

[1]: https://github.com/gggeek/phpxmlrpc

ipso/ADOdb,ipso/ADOdb