DOCS-558 add name, cache options to db.collection.ensureIndex()

Author: Ed Costello

source/reference/method/db.collection.ensureIndex.txt

@@ -52,6 +52,8 @@ db.collection.ensureIndex()
    ==================== =================  =========
     background           true or false      false
     unique               true or false      false
+    name                 string             none
+    cache                true or false      true
     dropDups             true or false      false
     sparse               true or false      false
     expireAfterSeconds   integer            none
@@ -69,6 +71,14 @@ db.collection.ensureIndex()
                            or keys matches an existing value in the
                            index.
 
+   :option string name: Specify the name of the index. If unspecified,
+                        the index name will be generated by concatenating 
+                        the names of the indexed fields and the sort order.
+                        
+   :option Boolean cache: Specify ``false`` to prevent caching of this
+                          :method:`db.collection.ensureIndex()` call in
+                          the index cache.
+
    :option Boolean dropDups: Specify ``true`` when creating a unique
                              index, on a field that *may* have
                              duplicate to index only the first