s/similarily/similarly/

Remove reference to (no longer) fixed 4 mbyte kernel memory being reserved,
it is now dynamic.

branches: 1.17.2;
Bump date for previous.

Provide variants of the -s option to allow limiting the tmpfs dynamically
at mount time to 1/Nth or to N percent of the available ram.

Improvements from jmc@openbsd.

branches: 1.14.20; 1.14.26;
Convert TNF licenses to new 2 clause variant

branches: 1.13.4; 1.13.6;
The first non-optional parameter is ignored by this program.

ok'ed by jmmv@.

branches: 1.12.4; 1.12.6;
s/tons/lots/, per simonb@'s suggestion. This looks more formal.

Nicer macro usage.

Note that meta data is stored in non-pageable memory and the problems this
may carry. Suggested by Greg Troxel in private mail.

tmpfs is not considered experimental any more. OK'ed by core@.

Point to the share/examples/fstab/fstab.ramdisk file for some more information.

Add an EXAMPLES section. Requested by martti@ to clarify the purpose of
the field before the mount point.

Kill reference to tmpfs(9). Noticed by "pancake".

Ignore case of trailing unit specifiers in size measures to remove confusion.

Inherit owner, group and mode of the mount directory so that mounting a
tmpfs over, e.g., /tmp, is trivial.

Kill the tmpfs(9) manual page; it was just documenting internal details of
tmpfs' "API" and was already rotting.

Instead, merge all the relevant comments into the code. This includes
acknowledgements to Google's Summer of Code 2005 program (they were in the
AUTHORS section of tmpfs(9) before), so all the files need to be changed
to include this sentence alongside the title. (Note that this was not a
requirement of the program.)

wiz@ remembers that the preferred way to spell file-system in NetBSD is
file system.

Initial addition of tmpfs, an efficient memory file-system. This project
was developed as part of Google's Summer of Code 2005 program. This
change adds the kernel code, the mount_tmpfs utility, a regression test
suite and does all other related changes to integrate these.

The file-system is still *experimental*. Therefore, it is disabled by
default in all kernels. However, as typically done, a commented-out
entry is added in them to ease its setup.

Note that I haven't commited the required mountd(8) changes to be able
to export tmpfs file-systems because NFS support is still very unstable
and because, before enabling it, I'd like to do some other changes.

OK'ed by my project mentor, William Studenmund (wrstuden@).