XDR: Stop the madness

XDR: Stop the madness

We currently attempt to align our XDR implementation with what may
be provided by the host system. This leads to a huge amount of parameter
fudging, and general pain and misfortune. However, the only place that
we still actually use the system XDR is for UKERNEL builds.

Change this so that we use our XDR everywhere. Fix all of our type and
function definitions so that they're standard. Remove the warning
inhibitions.

Change-Id: I53f4539e50eacb4e0691d8d3d6546bbfb7438358
Reviewed-on: http://gerrit.openafs.org/1340
Reviewed-by: Chaz Chandler
Tested-by: Chaz Chandler
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>