* master: (118 commits)
  nodefs: split the dual function of OperationStubs
  nodefs: regularize method naming
  nodefs: test Mknod
  nodefs: by default return input offset for Lseek
  nodefs: rename DefaultOperations to OperationStubs
  nodefs: doc nits.
  nodefs: port utimens and allocate from fuse/nodefs
  fuse: add cancel channel to Release call
  nodefs: provide Inode.Root rather than Inode.IsRoot
  nodefs: drop InodeOf
  nodefs: embed Inode directly in DefaultOperations
  nodefs: fix outdated comment
  nodefs: fix double syscall.Close
  splice: more verbose panic if discarding pipe pair fails
  nodefs: document ToErrno, NewListDirStream
  nodefs: only set default timeout if Entry/Attr does not specify a timeout
  fuse: add Timeout methods to EntryOut and AttrOut
  nodefs: return ENOTSUP rather than ENOSYS
  nodefs: make everything compile on darwin
  nodefs: use syscall.Errno instead of fuse.Status
  ...