Added to the client class the possibility to use Digest and NTLM authentication methods (when using the CURL library) for connecting to servers and NTLM for connecting to proxies

Added to the client class the possibility to specify alternate certificate files/directories for authenticating the peer with when using HTTPS communication

Reviewed all examples and added a new demo file, containing a proxy to forward xmlrpc requests to other servers (useful e.g. for ajax coding)

The debugger has been upgraded to reflect the new client capabilities

All known bugs have been squashed, and the lib is more tolerant than ever of commonly-found mistakes