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.
[Buddy Time]
type=incomplete
depends=purple
provides=buddytime
summary=Quickly see the local time of a buddy
description=%(summary)s
authors=Gary Kramlich,Richard Laager
introduced=2.2.0
[Buddy Time (Pidgin UI)]
type=incomplete
depends=pidgin buddytime
provides=gtkbuddytime
summary=Pidgin user interface for the Buddy Time plugin
description=%(summary)s
authors=Gary Kramlich,Richard Laager
introduced=2.2.0