Reduce struct node size

* Replace the stat values with a crc32b of them instead (for auto-cache)
* Replace char flag with bitfield
* Remove node generation. nodeid is an unsigned 64bit int. Would take 500K+ years
  to rollover at 1M nodes per second.

libfuse/Makefile

@@ -32,14 +32,15 @@ INSTALLMAN1DIR = $(DESTDIR)$(MAN1DIR)
 AR ?= ar
 
 SRC   = \
-	lib/fuse_node.c \
 	lib/buffer.c \
-	lib/fuse_dirents.c \
+	lib/crc32b.c \
 	lib/fuse.c \
+	lib/fuse_dirents.c \
 	lib/fuse_kern_chan.c \
 	lib/fuse_loop_mt.c \
 	lib/fuse_lowlevel.c \
 	lib/fuse_mt.c \
+	lib/fuse_node.c \
 	lib/fuse_opt.c \
 	lib/fuse_session.c \
 	lib/fuse_signals.c \