DRILL-1684, DRILL-1517, DRILL-1350: Profile and cancellation updates
- Remove any storage of persisted profiles.
- Store a separate query info object for active queries.
- Update cancellation and running profile loading to query foreman server.
- Make file store support HDFS APIs
- Update PStoreProvider to use configuration to decide if you want PERSISTENT, EPHEMERAL, or BLOB storage rather than separate interfaces.
- Update ZkPStore's persistent mode to leverage a cache and respond to changes rather than actively probing values.
- Update ZkPStore's cache to be effectively write-through.
- Automatically delete deprecated or default value options from PStore.
