Now an add-on can contain multiple protocols, and the protocol API has
changed. An add-on must now export protocol_count() and protocol_at(),
with the latter replacing protocol(). protocol_count() returning the
amount of protocols in a given add-on, and protocol_at(i) giving a
new CayaProtocol* "at" the given index.
CayaProtocol has also been changed, adding Signature(),
FriendlySignature(), Icon(), Path(), and SetPath(). The reasoning is
that different protocols (even within a single add-on) will have
different signatures and icons, so this data should be accessible from
the protocol itself.
CayaProtocolAddOn now has CountProtocols() and ProtocolAt(i), allowing
the accessing of multiple protocols. A CayaProtocolAddOn can be given a
default protocol index in the constructor, whose protocol will be
returned with Protocol(). Version() was also moved from CayaProtocol to
CayaProtocolAddOn.