Yahoo! Japan as a separate PRPL

[Mark Doliner]

Right now we have a "Yahoo Japan" checkbox on the advanced tab of the
account editor when modifying a Yahoo account.  Yahoo and Yahoo Japan
are separate networks that just happen to use the same protocol.  And
I've realized that it is possible to have the same username on each
network, and the usernames are totally independent accounts with
separate buddy lists.  For anyone who wants to try this, note that you
might have to have to create the Yahoo Japan account first (I don't
remember for sure).

And so it kind of makes sense to register a separate PRPL for Yahoo
Japan.  This way people with the same account on each IM network can
have both accounts signed on in Pidgin, and can have their chatlogs
separate, separate buddy list, etc.

How do people feel about this?  It would be similar to what we do with
oscar, where we call PURPLE_INIT_PLUGIN() once for AIM and once for
ICQ.

-Mark