Add support for named buffers. If you don't name a buffer, things work
much as before - buffers are automatically named "buffer0000",
"buffer0001" and so on and ordered as a stack. Buffers can be named
explicitly when creating ("loadb -b foo" etc) or renamed ("setb -b
buffer0000 -n foo"). If buffers are named explicitly, they are not
deleted when buffer-limit is reached. Diff from J Raynor.
Add a copy mode key binding to copy to a named buffer. From J Raynor.
If multiple arguments are given to new-session, new-window,
split-window, respawn-window or respawn-pane, pass them directly to
execvp() to help avoid quoting problems. One argument still goes to "sh
-c" like before. Requested by many over the years. Patch from J Raynor.
Remove some m->m_pkthdr.rcvif dereference to help for upcoming
receiving pointer -> index conversion.  No functional change.

ok claudio@, mikeb@, lteo@
skip incomplete entries in /etc/hosts and /etc/networks
fix null deref spotted by Seth Hanford, pinpointed by dtucker@

ok florian@
Nuke another pointless dev_bsize variable always set to 512 and use
DEV_BSIZE. David Vasek says it still works the same on 4K-byte-sector
device. i.e.  prints one value incorrectly. For which a fix should
be following soon.
ohash stuff in libutil now;
zap trailing whitespace;
various macro fixes;
pass SA initiator not the exchange initator to sa_address(); ok mikeb@
While Rev 1.285 fixed a RB tree corruption it caused a TAILQ corruption
in the case where the rdomain was not switched. Make sure ifa_add() is
only called if ifa_del() was called previously. Hopefully we got all the
corruption fixed.
With and OK mpi@
- document two escape sequences as extensions in STANDARDS
- document undefined behaviour for unlisted formats in
combination with `#'; guenther helped me organise this into a saner
piece of text

ok guenther
for non-valid combinations with `#', instead of trying to list them all,
simply say all other combinations are behaviour undefined;

ok guenther, who reminded me to change these too;
We don't need no stinkin' 'extern long dev_bsize;'. At least not since
fsck_ffs stopped providing it.
sync some of the text of ENVIRONMENT with more(1), and cut some
verbiage;

ok millert
Don't allow multiple buffers with the same name, from Thomas Adam.