A few changes for p9p on OS X:

Here's a set of patches and a merge to get fuse and a few other bits
working on OSX 10.5:

2916.patch :: [9pfuse] updates to support current MacFUSE
2921.patch :: [file.c] X3F support
2922.patch :: [mount] macfuse change
2923.patch :: (tip) merge in macfuse changes and file update

2916.patch is needed to use the latest MacFUSE release for OS X 10.5.
Skip's been testing the patch w/ OS X 10.4.