Gracefully handle design document updates with malformatted structure
Expose language and views from #mrst{} records
Expose access to the file descriptor for monitoring.
Add an API to see if the index file exists
Don't use delayed send when a resp hasn't started

This is for a bit of an edge condition if we get an error before we
start streaming data through the coordinator. Easily triggered by
setting all copies of a shard to maintenance mode.
Update to use couch_stats
Merge data_size calculations for views

This adds the new data size information to view info data.

BugzId: 27061
squash! Add an API to see if the index file exists
Monitor the newly compacted view file