Update to slice 0.7
Use async http responses for task communication

Add AsyncResponseUtils to help bind ListenableFuture to AsyncResponse
Add MoreFutures.addTimeout to add timeouts to ListenableFutures
Change TaskResource to use async JAX-RS resposnes
Change SqlTaskManager to return futures for task info and buffer results
Allow waiting for task info and buffer results before either are created
Add support for closing tasks and buffers before they are created
Simplify buffer code and state machine
Make SqlTaskManager and SqlTask lock free
Change SharedBuffer.getInfo not lock the buffer
Add more information to StatementClient error messages
Upgrade to Airbase 25-SNAPSHOT