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.
[Enhanced History]
type=broken
depends=pidgin
provides=enhancedhist
summary=An enhanced version of the history plugin
description=%(summary)s Grants ability to select the number of previous conversations to show instead of just one.
authors=Andrew Pangborn
introduced=2.3.0