store PLUGINS_DIR at load time
store PLUGINS_DIR at load time

With this commit, peru is Python 3.3 compatible again.

buildinspace/peru,ierceg/peru,scalp42/peru,enzochiau/peru,olson-sean-k/peru,nivertech/peru,buildinspace/peru,scalp42/peru,enzochiau/peru,oconnor663/peru,olson-sean-k/peru,ierceg/peru,nivertech/peru,oconnor663/peru