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.
This is backporting code from the full FUSE library in order to support
ioctls. The fuse protocol level negociated is now 7.18 instead of 7.8.
A fallback protocol to 7.8 is provided for compatibility with older kernels.
32-bit ioctls are not supported by a 64-bit library