Yelp/mrjob — pull request #442 by icio (2012-04-12 17:54:34+00:00)
Title: Correct sort-split file ordering

Because the current flow of `LocalMRJobRunner` depends on the order of keys coming out of an `enumerate` key we occasionally/inconsistently find that the parts are in the correct order post-sort:

```
> /usr/bin/python test.py --step-num=0 --reducer --strict-protocols /tmp/snapshot/test.paul.20120412.175015.452279/input_part-00001
writing to /tmp/snapshot/test.paul.20120412.175015.452279/step-0-reducer_part-00000
> /usr/bin/python test.py --step-num=0 --reducer --strict-protocols /tmp/snapshot/test.paul.20120412.175015.452279/input_part-00000
writing to /tmp/snapshot/test.paul.20120412.175015.452279/step-0-reducer_part-00001
```

Notice `input_part-00001` writing to `step-0-reducer_part-00000` and vice-versa.

This alteration ensures that the `task_num, file_name` pairs are maintained correctly and ordering is consistent.