1129817 - prepend process id and thread id if line is split

By including a unique identifier, it is possible to separate logs that are generated at the same time.

 [Bugzilla-1129817](https://bugzilla.redhat.com/show_bug.cgi?id=1129817)
Ah, I think you might be right about the thread id being so long. However, I think this indicates another problem. Here's the log messages that came from the above code:

```
Sep 17 15:47:20 notepad pulp: randy:INFO: 123456789012
Sep 17 15:47:20 notepad pulp: randy:INFO: This is a'OK
Sep 17 15:47:20 notepad pulp: randy:INFO: (2285-140590788294400)This is
```

See the "This is"? The problem I think is that the code is now allowing messages that are longer than MAX_LENGTH:

```
>>> len("pulp: randy:INFO: This is a'OK")
30
>>> len("pulp: randy:INFO: (2285-140590788294400)This is")
47
```

Are you sure it's correct to reset the relative_ending_index on line 217?