Inteface update
update to allow passing predicates to data_buffer (allows use of multi
keys)
update interface to allow pair of string that we can identify ranges or
sessions (files in our case) for deletion (clean up).
Initial code and WIP for range based delete in data_buffer.
Fixed bug in DataBuffer.
Merge remote-tracking branch 'origin/next' into ResourceHandler
Changed launch::async to default launch policy for LocalStore.