The support for ioctls has been added to fuse when using protocol 7.18,
and an equivalent upgrade has been done in fuse lite with commit [ae9aee].
For old kernels, a fall back to protocol 7.8 was implemented, but this
appears not to be supported in not-so-old kernels (e.g. 2.6.35).
With this patch, the fall back protocol is set to 7.12 or to the highest
level supported by the kernel.