allow querying _all_docs using View functions

specify "" as design document
and "_all_docs" as view name

client.go

@@ -469,7 +469,11 @@ func (b *Bucket) ViewCustom(ddoc, name string, params map[string]interface{},
 		}
 	}
 
-	u.Path = fmt.Sprintf("/%s/_design/%s/_view/%s", b.Name, ddoc, name)
+	if ddoc == "" && name == "_all_docs" {
+		u.Path = fmt.Sprintf("/%s/_all_docs", b.Name)
+	} else {
+		u.Path = fmt.Sprintf("/%s/_design/%s/_view/%s", b.Name, ddoc, name)
+	}
 	u.RawQuery = values.Encode()
 
 	res, err := HttpClient.Get(u.String())