Big changes on the cgf-dev-branch branch

[Christopher Faylor <cgf at redhat dot com>]

I'm using part of my vacation to revamp cygwin's device handling.  I'm
adding a 'dev' element to the path_conv and fhandler structures.  This
element will hold true linux-like major and minor device information.
There is also a currently unused field for block and character devices.

I've just implemented on-disk device files such that you can do

    mknod bob 5 0 c

and then a 'echo hello >bob' will go the the tty since 5, 0 is the
major/minor numbers for /dev/tty.

Currently, devices are just symlinks to something funky.

This all started because I wanted to implement a fifo using cygwin's new
peer-to-peer process communication and got bogged down in trying to
represent something like a device on disk.

The branch is a somewhat fragile state right now but things seem to be
coming along nicely.  My trick for tomorrow will be to properly display
ownership and protection for on-disk devices.

FYI,
cgf