Destructors for pointer/keyboard/touch

[Rob Bradford]

Hi folks,

One of the prerequisites for pointer lock support is the client being able to
request the destruction of the client. Kristian wrote the patches below some
time ago and i've rebased and bumped the versions appropriately. Unfortunately
in order to maintain API we must call our destructor _release and _destroy will
be an autogenerated client-side version that will not send a request to the
server.

As well as the patches to add the protocol patches to support this request in
Weston are also provided along with a change to make toytoolkit use the new
request.

Cheers,

Rob