- Make MAXTSIZ, DFLDSIZ, MAXDSIZ, DFLSSIZ, MAXSSIZ, SGROWSIZ loader
  tunable.
- Change TUNABLE_*_FETCH to have a return value of 0 if the variable
  was not found or successfully converted and true otherwise.
- Use vm_offset_t instead of caddr_t to fix a warning and remove
  two casts in kern_exec.c.

is an application space macro and the applications are supposed to be free
to use it as they please (but cannot).  This is consistant with the other
BSD's who made this change quite some time ago.  More commits to come.

made "static" and (2) initialized but unused variables.

"vmstat -s" reports the correct value on the Alpha.

Submitted by:	Hidetoshi Shimokawa <simokawa@sat.t.u-tokyo.ac.jp>

code still left in there.  The macros it describes disapeared some-
time since 4.4BSD lite.

PR:		7246
Reviewed by:	phk
Submitted by:	Stefan Eggers <seggers@semyam.dinoco.de>

ready for it yet.

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.

	Re-enables the RSS limiting, and the routine is now tail-recursive,
	making it much more safe (eliminates the possiblity of kernel stack
	overflow.) Also, the RSS limiting is a little more intelligent about
	finding the likely objects that are pushing the process over the limit.

	Added some sysctls that help with VM system tuning.

New sysctl features:
	1)	Enable/disable lru pageout algorithm.
		vm.pageout_algorithm = 0, default algorithm that works
			well, especially using X windows and heavy
			memory loading.  Can have adverse effects,
			sometimes slowing down program loading.

		vm.pageout_algorithm = 1, close to true LRU.  Works much
			better than clock, etc.  Does not work as well as
			the default algorithm in general.  Certain memory
			"malloc" type benchmarks work a little better with
			this setting.

		Please give me feedback on the performance results
		associated with these.

	2)	Enable/disable swapping.
		vm.swapping_enabled = 1, default.

		vm.swapping_enabled = 0, useful for cases where swapping
			degrades performance.

		The config option "NO_SWAPPING" is still operative, and
		takes precedence over the sysctl.  If "NO_SWAPPING" is
		specified, the sysctl still exists, but "vm.swapping_enabled"
		is hard-wired to "0".

Each of these can be changed "on the fly."

<sys/types.h> (if KERNEL is defined).  This allows removing bogus
dependencies on vm stuff in several places (e.g., ddb) and stops
<vm_param.h> from depending on <vm_param.h>

Added declaration of boolean_t to <vm/vm.h> (if KERNEL is not
defined).  It never belonged in <vm/vm_param.h>.  Unfortunately,
it is required for some vm headers that are included by applications.

Deleted declarations of TRUE and FALSE from <vm/vm_param.h>.  They
are defined in <sys/param.h> if KERNEL is defined and we'll soon
find out if any applications depend on them being defined in a vm
header.