Close view files cleanly on DB create/delete

The shutdown_sync was actually interfering with a clean shutdown
initiated by the index processes themselves when they received a 'DOWN'
message from their monitoring of the DB process.  The explicit 'delete'
cast message in this patch is very probably redundant, but it makes the
intent clear.  The important bit is to let the index process terminate
*and* get confirmation of the termination before attempting to nuke the
directory.

COUCHDB-1364

src/couch_index/src/couch_index_server.erl

@@ -160,7 +160,9 @@ reset_indexes(DbName, Root) ->
     % shutdown all the updaters and clear the files, the db got changed
     Fun = fun({_, {DDocId, Sig}}) ->
         [{_, Pid}] = ets:lookup(?BY_SIG, {DbName, Sig}),
-        couch_util:shutdown_sync(Pid),
+        MRef = erlang:monitor(process, Pid),
+        gen_server:cast(Pid, delete),
+        receive {'DOWN', MRef, _, _, _} -> ok end,
         rem_from_ets(DbName, Sig, DDocId, Pid)
     end,
     lists:foreach(Fun, ets:lookup(?BY_DB, DbName)),