KliegSearcher: Quit cleanly on EOF (ctrl-D)
Index from S3 instead of the local filesystem

Read the Metaminder and Publisher data from S3 instead of the local
filesystem.  Code is shamelessly copied from klieg's own DataLoader.java
as well as from james, and the copying process may have significantly
uglified the code.  Still, it's amazing what you can do with cut and
paste these days.

The following environment variables need to be set:
export AWS_ACCESS_KEY=aws access key id
export AWS_SECRET_KEY=aws secret key

NOTE: Error handling is nonexistent.  Be careful out there.