for pointing out this evaded the last commit

- new installs wont have existing ifaliases
- updates dont touch /etc
- manual updates of /etc/ should know what they're doing anyway
fwiw, see hostname.if(5) alias functionality has moved here for better
overall network configurability

changed so files are e.g. backups/etc_passwd not backups/_etc_passwd

Clarify point about always NUL-terminating.

symbolic links (the -h flag is for compatibility only); millert@ ok

add commented out entry into sysctl.conf for vfs.nfs.iothreads

REMEMBER TO UPDATE YOUR TREE BEFORE REBUILD! This *will* be used shortly.

when the monitor is blanked.

problem due to type promotion).  PR 1228.

Enable by setting DEBUGLIBS=yes in /etc/mk.conf, then -g libraries will get
installed in /usr/lib/debug.  This directory will be searched first if
gcc is given the -g flag during the link stage.

.. ok deraadt@, millert@

device is opened by default).
Don't open the file w/o adding a /dev/ prefix unless the file has
a '/' in it.  This prevents problems where someone says "disklabel
sd0" with a file called "sd0" in the cwd.
The OPENDEV_DRCT flag has been deprecated as it is the the default
behavior and always has been.
Add checks for >= MAXPATHLEN and return ENAMETOOLONG in that case.