Add naive semiparallel processor

[txus]

A naive semiparallel processor.

It chunks consecutive GET requests and executes each chunk in a map of threads.

To use it, simply pass sequential: false in the request parameters.

[arsduo]

Have an explicit option -- params["strategy"] or whatever: "sequential", "semiparallel", "parallel", etc.

[arsduo]

After writing a spec for the Batch API, I'm thinking this should be the default. There's really no need for fully sequential. I'll poke around with this later this week.

[lukelex]

Any progress on this?

[dvgica]

I would love to see some movement on this as well.

[arsduo]

@lukelex @DWvanGeest I haven't worked on this project in a while, but hope to catch it up this weekend. Did you ever test @txus' pull request? Does it work for you? If so, I'll merge it in.

[arsduo]

Actually, there's a later pull request that does full parallel processing with Celluloid: #33 -- if you're still interested in parallel processing and could try that out and see if that works for you, that's probably the direction this project should go.

[jeremyhaile]

So should this commit be closed in favor of #33?