- add "--pci 00:1f.3" option to easily specify a PCI device instead of having to
  use --bus, --dev, and --func.

- memset + snprintf looks dubious

- pci_get_ndevs should be deprecated, applications shouldn't be relying on this

- In pci-ops.c - config_block_op:
  Update len with remaining allowed size once op() returns EIO
  so that we get short reads/writes implemented by leaving it to pciaccess

- Upstream hurdish access method + x86 fixes to libpciaccess

  BTW we could also support libpci.
