Resolving a view may create a pipeline that exceeds 16 MB

When creating a sequence of views on views, the final resolved pipeline may exceed the maximum document size. This will be bad if the view is on a sharded collection, as the error response from the primary shard to mongos will be too large to handle.

We should impose some sort of limit when creating/modifying a view definition and/or check the size of the resolved view on resolution and fail if it is too large.