qom: quick and dirty QOM filesystem based on FUSE

qom: quick and dirty QOM filesystem based on FUSE

Here's an example session:

anthony@titi:~/git/qemu/QMP$ QMP_SERVER=/tmp/server.sock ./qom-fuse tmp
anthony@titi:~/git/qemu/QMP$ ls tmp
machine  sysbus  type
anthony@titi:~/git/qemu/QMP$ ls tmp/machine
i440fx  peripheral  peripheral-anon  type  unattached
anthony@titi:~/git/qemu/QMP$ ls tmp/machine/i440fx
ioapic  parent_bus  pci.0  type
anthony@titi:~/git/qemu/QMP$ ls tmp/machine/i440fx/pci.0
child[0]  child[1]  child[2]  child[3]  child[4]  child[5]  type
anthony@titi:~/git/qemu/QMP$ ls tmp/machine/i440fx/pci.0/child[4]
addr                 legacy-addr                 multifunction  type
command_serr_enable  legacy-command_serr_enable  parent_bus
ide.0                legacy-multifunction        rombar
ide.1                legacy-romfile              romfile
anthony@titi:~/git/qemu/QMP$ cat tmp/machine/i440fx/pci.0/child[4]/type
piix3-ide
anthony@titi:~/git/qemu/QMP$ ls -al tmp/machine/i440fx/pci.0/child\[4\]/parent_bus
lrwxr-xr-x 2 anthony anthony 4096 1969-12-31 18:00 tmp/machine/i440fx/pci.0/child[4]/parent_bus -> ../../../machine/i440fx/pci.0

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>