pidgin/purple-plugin-pack

Re-add purple2 compatibility with #if PURPLE_VERSION_CHECK(3,0,0) blocks

Based on previous commits between 2.7.0 and now, this is sorta like reverting
those changes partially.
[Album]
type=default
depends=pidgin
provides=album
summary=Archives buddy icons
description=%(summary)s
authors=Richard Laager,Sadrul Habib Chowdhury
introduced=2.0.0