Don't associate http requests with server instances

There is very little correlation between a memcached server and the
views it conducts with respect to our code. Making all requests be
parented by the instance simplifies the internal structure

Change-Id: I9c4ff581306a3b63c596dc453961f5a8507747ad
Allow timeouts for view requests

Change-Id: I4285454b6309c6993befa1fcc4f12b38ef8c208d