Added kernel private node_monitor.h header.

Moved definition of "struct io_context" from fd.h to vfs.h.
Introduced new fs/ directory; some cleanups to come.
Added node monitor syscalls.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@2479 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/ksyscalls.h

@@ -127,6 +127,9 @@ enum {
 	SYSCALL_UNREGISTER_IMAGE,		/* 115 */
 	SYSCALL_GET_IMAGE_INFO,
 	SYSCALL_GET_NEXT_IMAGE_INFO,
+	SYSCALL_START_WATCHING,
+	SYSCALL_STOP_WATCHING,
+	SYSCALL_STOP_NOTIFYING,			/* 120 */
 };
 
 int syscall_dispatcher(unsigned long call_num, void *arg_buffer, uint64 *call_ret);