procfs ctl interface

[Eric Badger]

I started working on a change that will perturb procfs' ctl interface to 
some degree. In looking closer at procfs, it seems like it has been 
pretty well broken for use as a debugging interface since at least 9.3 
(the oldest system I have handy). Is there any reason to maintain this 
interface at all? If anything, it should perhaps be made into an 
alternate front end for ptrace() rather than being entirely separate, 
but I'm not sure I see the value in that.

Thanks for any thoughts/opinions.

Eric