equal, larger, respectively instead of 0/1 for non/equal. This
will allow sorting the buffers for faster matching in libpuffs.
While here, change the name from respcmp to framecmp, as that better
reflects the purpose.
NOTE! there is no obvious way to make compilation fail for file
systems which may already be using this feature (although I don't
think there are any outside our tree, as the feature is two weeks
old). Nevertheless, non-updated file systems will fail very quickly.
Works, but lots of little things to nibble on:
* fix permissions to work better
* limit the amount of open files required
* do constant folding with psshfs code
* support authentication
etcetc.