Handle private messages, both ways

Handle the ACTION (/me) IRC command, both ways

Connect to localhost instead of the served hostname

Because the XMPP component connection is only available locally, the XMPP
servers proably only listen on 127.0.0.1 instead of 0.0.0.0.

Handle IRC QUIT command

Fix the include of the config.h

And actually use the values found by cmake

Properly detect iconv features to compile

Add include for perror

Use the Expat library directly instead of relying on expatpp

And now we handle namespaces, yay.
And a nice little test.

Aaaand, I forgot to add files

Implement part and join, both ways

Remove IRC colors from the body when forwarding it to XMPP

Cosmetic

Check UTF-8 encoding, and convert strings to UTF-8

Handle conversion errors properly by inserting � instead.  Add a binary
header to provide portable way to write binary literals (I like them) Also
add a test file.  ref #2404

Send and receive messages

Also correctly respond to PING with the id, escape some XML content, but not
always

Add make_unique.hpp and split.hpp

Implement the Bridge class to translate between the two protocols

Add all useful classes as well: Jid, Iid, IrcChannel, IrcUser etc to
properly keep the informations about what we receive from the IRC server.

Only handle the MUC join stanza, and send the list of users in the IRC
channel to the XMPP user, and the IRC channel’s topic, for now.

Add FindCryptoPP to the cmake search stuf

Exit the poller when it handles no connection at all

Add a basic XMPP component implementation, doing the authentication