less: upgrade to v581.2.

(cherry picked from commit 50d31dbc6e2bc3aa6007edb8cdecbcb84e85d6c0)

less: upgrade to v581.

(cherry picked from commit 2235c7feac959bcc9ddfd6a2bc6be32102b1f84c)

Git Hash: c5c5683eb6c4e1d80e02e1e23e5c9bfc8f83c80b
Git Author: delphij@FreeBSD.org

MFC r367005: MFV r366990: less v563.

Relnotes: yes

MFC r349549: MFV r349535: less v551.

Relnotes: yes

MFC r316339,317396,317829,326010,329554: less v530.

Relnotes: yes

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFV r293125: less v481.

MFC after: 1 month
Relnotes: yes

MFV: less v451.

MFV: less v449.

MFV: Update to less v443.

MFC after: 1 month

Update less to v436. This is considered as a bugfix release from vendor.

Major changes from v429:
* Don't pass "-" to non-pipe LESSOPEN unless it starts with "-".
* Allow a fraction as the argument to the -# (--shift) option.
* Fix highlight bug when underlined/overstruck text matches at end of line.
* Fix non-regex searches with ctrl-R.

Approved by: re (kensmith, kib)

Update to less v429.

This commit was generated by cvs2svn to compensate for changes in r170256,
which included commits to RCS files with non-trunk default branches.

/home/delphij/m

Import less v394

Import less v381.

Import the [now] dual licensed version 3.5.4 of less. It is
distributed under your choice of the GPL or a BSD style license.

Reviewed by: peter
Obtained from: http://home.flash.net/~marknu/less/