w32: addpm.exe -> usethis.exe?

[Lennart Borgman <lennart.borgman.073@student.lu.se>]

A rather long time ago I rewrote addpm.exe and renamed it to 
usethis.exe. I made two important changes:

1) It adds/changes emacs_dir to HKCU if HKLM can not be used.

2) No icon is added to Program Manager any more. In my opinion Emacs 
should be run as a server on w32 and that icon starts a standalone Emacs 
without any server capabilities.

The last point may need some explanation. If I get it right Emacs is 
often started first as a standalone application and then gnuserv or 
emacsserver are started later. That is in my opinion not the best way to 
do it. Instead I believe that gnuclient or emacsclient should start 
Emacs and tell it to start gnuserv/emacsserver if needed.

Doing it that way makes it possible to implement shortcuts to Emacs (ie 
gnuclient) on all places where you can do so in w32. You can also this 
way easily use Emacs as an edit server for other apps that allow you to 
do so.

So the shortcut/icon in Program Manager should point to 
gnuclient/emacsclient instead and should be added when those are added.

BTW, I doubt that emacsserver/client will be ready for w32 before 
release. Does anyone have any updates on this? There is a version of 
gnuserver/client that we can use instead however.

The source for usethis.exe can be found at 
http://ourcomments.org/Emacs/DL/build/.