finding top-level dirs on windows

[Frank Osterfeld]

Hi,

both Windbus and kdelibs find their installation directory by using the path 
to their binary (dbus-daemon.exe and libkdecore.dll respectively) and deduce 
the top-level installation directory from there. Both work with the 
assumption that the binaries are located in %INSTALLDIR%\bin.
In Gpg4win, we want to get rid of bin\ completely, as all other .exe and .dll  
files are already installed directly to %INSTALLDIR%. These two exceptions 
require several workarounds so all binaries and other resources are found 
correctly. 

I'd like to add the possibility to specify the windbus and KDE installation 
directory at installation time by adding an InstallLocation registry entry.
getKde4Prefix in kkernel_win.cpp and dbus_get_install_root can use that path 
then if it's present.
That  might also be useful for all of KDE on Windows later, when third parties 
want to ship software separate from the main KDE distribution and need to 
find an existing KDE installation.

What do you think of it? Is such a registry entry the way to go, are there 
alternatives? (maybe even implemented ones I haven't found yet)

Regards,

-- 
Frank Osterfeld -- frank at kdab.net
Klarälvdalens Datakonsult AB, Platform-independent software solutions