Modifying extract

Extract now works off of a single element instead of an array of
elements. This will be useful for highland integration
Modifying craigslist to use streams now

This will now use the highland stream interface as opposed to the
promise based interface. It is a lot faster.
Simplifying flatMap

There is no reason to go out to another map function on the stream with
flatMap
Renaming files and removing leveldb

The insertion is a simple pipe command now which is pretty nice.
Adding a job abstraction for lists

This should be helpful for running the job
Done
Merge pull request #5 from pspeter3/highland

Highland