Patch: Changed EventLog event SparkToThread to CreateSparkThread.

[Simon Marlow]

Donnie - when changing events you have to create a *new* event, and
deprecate the old one.  This is how we keep our log files parseable by
old versions of the tools.

Cheers,
   Simon

2009/4/22 Donnie Jones <donnie at darthik.com>:
> Changed EventLog event SparkToThread to CreateSparkThread; removed
> unnecessary thread_id, the event now only contains capability number
> and the created spark_thread id.
>
> Simon and Satnam: I also updated ghc-events library and ThreadScope to
> reflect this changes.
>
> Thank you.
> --
> Donnie Jones
>