Clean up make release procedure. But just make through
in distrib/mac68k/miniroot.

Reviewed by fredb, briggs
Add the machine id of PowerBook 190CS.
Move names for softfloat lib that _Qp functions call into _softfloat_
namespace
Unblock a few routines that are needed if 128bit support is being pulled in.
Added setreuid/setregid
Add ofromioctl(), needed since Christos added ioctl to the memory device's
cdev decl.
Split the (commented out) complete list of archs into separate lines
split alphabetically.  This makes it easier to add new archs without
having to do extensive reformatting.
implement COPYDIR for mtree and populate modes
Sort function declarations.
Fix some KNF whitespace nits.
Indent by tab and not two spaces.
document various supported environment variables, including MAKEOBJDIRPREFIX
provide check_DESTDIR and check_RELEASEDIR targets in <bsd.own.mk>
and use those rather than local versions
oops; should define check_DESTDIR before setting default for DESTDIR...
bring in latest ALTQ from kjc.
bring in latest ALTQ from kjc.  ALTQify some of the drivers.
Switch back to using vm_page_md (thanks chuq for finding the bug
in the code that made it unstable before!)
* Make pmap_is_{modified,referenced}() macros in pmap.h that just
  test the attributes in the vm_page_md directly.
* Clean up pmap_clear_{modified,referenced}().
* Delete now-unused pmap_testbit().
Include <sys/kernel.h> if UVMHIST is defined - the "cold" variable is
used in the UVMHIST_LOG macro.
Breakage reported by Chuck Silvers in private mail.
on redirect output, always try to attach target link layer address option.
Don't cast argument to ffs() to long.
Per discussion on port-alpha, noticed by Robert Elz.