Renamed query2_server_t to query_server_t.
Added changefeed.hpp
Filling out classes in changefeed.cc
Working on first changefeed implementation.
Adding changefeed manager to environment.
Refactoring changefeeds.
Checkpoint commit -- changefeeds are partially working.
Style fixes for changefeeds.
Adding write messages for changefeed subscriptions.
Adding functionality for serving changefeeds on shards.
Cleaning up changefeed types.
Checkpoint commit -- halfway through large changes.
Changefeeds+subscriptions are partially working.
Adding exception specifiers.
Logic for changefeed disconnection/completion.
Logic for changefeed queues going over array size limit.
Logic for closing changefeeds on shutdown.
Changefeed code no longer crashes on shutdown.
Changefeeds are partially working -- need to test more cases.
Improved changefeed write messages.