FileDescriptor will now keep a pointer to the original inode even after
opening it resolves to a character device.
Fixed up /bin/ls to display major and minor device numbers instead of size
for device files.
This required a fair bit of plumbing. The CharacterDevice::close() virtual
will now be closed by ~FileDescriptor(), allowing device implementations to
do custom cleanup at that point.
One big problem remains: if the master PTY is closed before the slave PTY,
we go into crashy land.
You're never gonna be right 100% of the time when guessing how much buffer
space you need. This avoids having to make that type of decision in a bunch
of cases. :^)
