mkfs.mfs fixup

 For the special case of crossbuilding minix on minix.
some etc fixes

	. split user-editable and system-owned files in etc/Makefile
	. mtab is a symlink, not a file now; remove it
	. force-install of certain system-controlled /etc files from
	  top Makefile
	. rename /etc/make.conf to /etc/mk.conf; and don't set $ARCH;
	  reduce difference in bsd.own.mk

Change-Id: I9f4bbb8d37ba80cba7dcfcf1a9a89e934910f579
kernel: rename realtime to monotonic, add realtime

Old realtime was used for both timers (where an accurate count of
all ticks is needed) and the system time. In order to implement
adjtime(2), these duties must be separated as changing the time
of day by a small amount shouldn't affect timers in any way nor
should it change the boot time.

Following the naming of the clocks used by clock_gettime(2). The
clock named 'realtime' will represent the best guess at the
current wall clock time, and the clock named 'monotonic' will
represent the absolute time the system has been running.
Use monotonic for timers in kernel and in drivers. Use realtime
for determining time of day, dates, etc.

This commit simply renames realtime to monotonic and adds a new
tick counter named realtime. There are no functional changes in
this commit. It just lays the foundation for future work.
libc: add clock_getres()/clock_gettime() system calls.

In order to make it more clear that ticks should be used for timers
and realtime should be used for timestamps / displaying the date/time,
getuptime() was renamed to getticks() and getuptime2() was renamed to
getuptime().

Servers, drivers, libraries, tests, etc that use getuptime()/getuptime2()
have been updated. In instances where a realtime was calculated, the
calculation was changed to use realtime.

System calls clock_getres() and clock_gettime() were added to PM/libc.
test69: add clock_getres() and clock_gettime() tests.
libc: add clock_settime() system call.

This also adds the sys_settime() kernel call which allows for the adjusting
of the clock named realtime in the kernel. The existing sys_stime()
function is still needed for a separate job (setting the boottime). The
boottime is set in the readclock driver. The sys_settime() interface is
meant to be flexible and will support both clock_settime() and adjtime()
when adjtime() is implemented later.

settimeofday() was adjusted to use the clock_settime() interface.

One side note discovered during testing: uptime(1) (part of the last(1)),
uses wtmp to determine boottime (not Minix's times(2)). This leads `uptime`
to report odd results when you set the time to a time prior to boottime.
This isn't a new bug introduced by my changes. It's been there for a while.
libc: add adjtime() system call.

Implement the adjtime() system call and add a test for it to test69.
Additionally, install the adjtime.2 and clock_*.2 man pages.
inet: silence message about exceptions

	. inet: silence message about exceptions not being implemented
	  for select(UDP)

This message generates a lot of noise with openntpd. Hide it unless DEBUG is
turned on.

Change-Id: I1527a9ca2583601d6087456062b4f675c80dd711
Remove obsolete warning in sys/sys/sysctl header

Change-Id: Idb9b10922d00d4b3886c8247f352cc4ec5fe17b4
top: a few fixes

	. fixed overflow in ticks compare function, causing
	  occasionally esp. the kernel to be mis-ordered by cpu
	  time
	. fixed some const string related warnings
	. fixed some variable name shadowing warnings

Change-Id: I02c177b1579bce164372f9b03f6b472537cc9e3e
Importing usr.bin/ftp
etcfiles: Improve the "install" message
Importing usr.sbin/rdate

Import the NetBSD rdate command and remove the Minix rdate command.
The default behaviour for both is the same. The NetBSD version adds
options to just display the time, adjust the time using adjtime(),
and set the time without printing the time.

Porting Notes:
 - Compiles cleanly out of the box without any warnings
 - Path changes from /usr/bin/rdate to /usr/sbin/rdate
 - checked pkgsrc for any usages of rdate (none found)
 - checked src for any usages of rdate (none found)

Testing:
 - all command line options work (tested with time.nist.gov server)
 - Native and cross build OK

Change-Id: I613449763891a896527f337999c006a970c3924c
tests/run: add test69 to setuids.

test69 requires superuser powers to adjust the time. This caused
the test to fail when run as a normal user. The patch adds test69
to the setuid list which will allow regular users to execute it.

Patch contributed by Antoine Leca.
Adding missing dependency on libraries for hdboot

 * Also cleanup a bit the makefile.
 * Also removing small inconsistency for arm builds where log would be
   skipped if doing a make hdboot, but not when cross-compiling.

Change-Id: Ic9e20655234a667ea8a967d05589d4df46c2d521
Removing include/minix/limits.h

This files defines two constants which are only used through
sys/syslimits. So they where moved there instead of including the file
and it was removed.

Change-Id: Iba3d220144dddf5d6411a6c66e2f223a1aafb50f
Downgrading to netbsd zlib version

Change-Id: I83cf73d8357ea34ab5e49fe15bd4c45ce54cac01