• Upgrade MongoDB driver.
• Prevent unbounded memory growth in a netsplit situation by putting an explicit
  limit (250K) on the number of outstanding plumtree-msgs in plumtree. If this
  limit is exceeded, delayed replication will be handled by active entropy.
• Handle uncaught error type in the vmq_ql_query handler.
• Make sure the peer_host can always be retrieved via the HTTP API. It was
  returned as an erlang tuple which caused the conversion to JSON to fail.
• Fix issue causing too few results to be returned from vmq-admin session show
  when used with filter options. This could happen when terms included in the
  filters also existed as erlang atoms.
• Plugin workflow improvements: move plugin development specific things into
  vernemq_dev.
• Fix error in the HTTP API interface. The alias /api/v1/sessions mapped to
  session list which is deprecated for session show.
• Fix max-age parse issue in vmq_webhooks (#527).