Attached patch adds support for kernel.maxfiles and kernel.maxproc items on HP-UX platform. the two items return values of "maxfiles" and "nproc" kernel tunables. This should work on all currently supported HP-UX versions.
Note that "maxfiles" tunable on HP-UX is just a soft limit - process can increase it within its environment if it needs to, up to value specified by "maxfiles_lim" tunable). This could be handled by introducing parameter to kernel.maxfiles item - either kernel.maxfiles[soft] (default), or kernel.maxfiles[hard].
Attached patch doesn't do this. If it is desired I can implement it in the future.