For better performance, do not use inject

I noticed we're using 'inject' in renderer which was discussed in GoGaRuCo as a performance offender:
http://www.youtube.com/watch?feature=player_detailpage&v=LWyEWUD-ztQ#t=1503

I replaced it with 'each' and did some benchmarking with the following code pieces:
https://gist.github.com/servercimen/2c50c6a16eb78606909e
https://gist.github.com/servercimen/141a4377c13f3165d30b

I saw performance gains between 10% and 18% depending on benchmarking parameters.
Let me know if this makes sense and if we can merge this to master.