TestSizeOf().
Added casBytes() to TestSizeOf().
TestSizeOfReqRes() / TestSizeOfMutation().
Skip view refresh if there are no ddocs.
Clear ddoc cache during ddoc deletion.
getViewsStorePathPrefix() helper function.
Remove all old view files during clearViewsStore().
More idiomatic nil handling.
Simplify file service.

Instead of having worker goroutines, we use a channel as a semaphore to
limit the number of concurrent requests for the file service, but
perform all the work synchronously.
Dynamically start workers in periodically.

This brings an idle cbgb down from somewhere approaching 90 goroutines
to under 20.
Merge remote-tracking branch 'upstream/master'