Pulling nupic.core binaries from S3 for builds.

This is still a WIP, but I wanted to get it pushed for review before I
continued testing different use-cases.
Stored S3 URL in a variable
Printing proper unpack location
Clarified absolute path in options comment
Use explicit boolean values
Merge pull request #20 from oxtopus/use-core-binaries

Use explicit boolean values
Merge pull request #1553 from rhyolight/use-core-binaries

Pulling nupic.core binaries from S3 for builds.