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.
#
# Makefile.mingw
#
# Description: Makefile for lastseen plugin.
#
PP_TOP := ..
PP = lastseen
include $(PP_TOP)/win_pp.mak