Document byType filter always uses temporary views

[ermyas]

The API (both deprecated and new) for filtering documents by type using a permanent view uses the couch temporary views API (/{db_name}/_temp_view) under the hood, instead of the appropriate couch view APIs ({db_name}/_design/{design_name}/_view/{view_name}). This of course is not the desired behaviour and is inefficient. The APIs for filtering using a permanent view might have to change instead to take a permanent view name.