[Nmh-workers] Artificial argv limits.

[Lyndon Nerenberg]

So my guess is that the argv limits are an artifact of the PDP-11 days.  I 
can't think of any reason to keep them around.  I think the best path forward 
is to just remove the limits and be done with it.

The result is that if an MH command runs up against the machines argv limit, it 
will fail.  If that's a problem for the user, they can use xargs(1).  The only 
additional work we should be doing is to ensure all the MH user commands are 
xargs friendly, and I am pretty sure that's already the case.

--lyndon