Hi YAFFSers

I have just checked in some YAFFS2 stuff. This will currently do YAFFS Direct 
and work with emulated 2kpage devices as well as supporting the older 512byte 
pages in YAFFS1 format via a tags compatability layer.

YAFFS2 supports YAFFS1 format for two reasons:
* Don't want to keep two code bases alive.
* During the development oif YAFFS2 I was able to speed up some things for 
YAFFS1 too. These have not been back-ported to the YAFFS1 code.

Next step is to finish off the Linux kernel support and utils....

-- Charles