This patch contains two major improvements:

First, thanks to Ari Huttunen, different door states show up as different
(configurable) characters on the screen.

Second, doors can now be entered/exited diagonally both for player and
monster.

Third, a gaggle of people credited in the appropriate files developed an
overlay manager for MS-DOS and MSC such that all the options of NetHack can
be supported.  See Install.dos and ovlmgr.* for further details.

In more minor news:

You no longer have to pick up food to eat it, and you no longer necessarily
resume eating your interrupted meal.

You can no longer get properties from wielding a non-weapon.

There is a new option, CLIPPING, which allows playing on small screens or
windows.

The multiple demon types portion of HARD has been split off into the new
INFERNO option.

The Macintosh port has been further refined.

The / command now takes configurable characters into account when identifying
items.

Leprechauns and lichs and nymphs and nagas had their letters switched so that
the more formidable monsters get capital letters.  Several new low-level
monsters were added.

Drawbridge interactions are much smarter, thanks to Kevin Darcy.

And a large number of minor bug fixes and efficiency enhancements.