Remove hbrep example as it's too out of date

The hbrep (postgres to hbase replication) example under src/examples/uploaders/hbrep is too out of date.
It doesn't account for changes to the thrift server. It would probably give more confusion then goodness if someone tried to use it.

I've been reworking it here:
http://github.com/tims/hbrep/tree/master

it works, but I'm still poking at it, and the docs are wrong.