fs_query: Make B_QUERY_WATCH_ALL part of the public API.

It seems to work well enough at this point, and is used in Tracker,
so why not?

Also update live_query to demonstrate the functionality.

headers/private/file_systems/QueryParser.h

@@ -39,8 +39,6 @@
 
 #	include <util/SinglyLinkedList.h>
 #	include <util/Stack.h>
-
-#	include <query_private.h>
 #endif	// !FS_SHELL
 
 #include <file_systems/QueryParserUtils.h>

headers/private/storage/query_private.h

@@ -1,10 +0,0 @@
-#ifndef QUERY_PRIVATE_H
-#define QUERY_PRIVATE_H
-
-
-// Send node monitor (B_ATTR_CHANGED, etc.) events for all
-// attributes on all entries in the query.
-#define B_QUERY_WATCH_ALL		0x0000F000
-
-
-#endif