Persistent Prov Repo should compress write-ahead-log files in chunks

Currently when we rollover a prov log, we compress the entire thing. This means that when we want to jump to a particular offset we have to open a GZIPInputStream and read through all of the data. If we instead compress the logs in chunks, we can actually jump to a particular chunk using FileInputStream.skip and then open a GZIPInputStream from there. Currently, this is by far the biggest bottleneck in the prov repo when doing queries.