Make the yumpkg5 module MUCH faster

benchmarked with a state with 52 packages

- before
real	0m58.023s
user	0m37.749s
sys	0m10.262s

- after
real	0m9.650s
user	0m6.192s
sys	0m1.728s


This now actually makes yumpkg5 faster than yumpkg!