DWT-Win now uses a resource file for WinXP theming

[Frank Benoit]

A long standing problem in DWT-Win is that the themed controls on winxp 
on some machines does not load images.

With WinXP a manifest must be loaded befor an "activation context" can 
be created. We have seen 4 different ways to do that

1.) Place the manifest file beside the application
2.) Write the manifest at application start to a temporary file and make 
windows to use that file.
3.) Link the manifest as a windows resource via linker option and 
compile rc file.
4.) Insert the windows resource after build with "resource injection"

1. seems the way that works, but we definitely don't want.

2. is the way we used in the past. As said, it turned out to work not 
everywhere. Probably there are ways to make it work, but several people, 
including me, have tried without success. Bummer!

3. and 4. need additions to the build process. In the past we already 
tried 3. and had problems.

Today i did experiments with 2..4 and 3 turned out to work now and to be 
the easiest for the build and use.

So i changed DWT-Win and DWT-Samples to work now with a resource file.

Plese take care of that, if you already have build a DWT-Win application.
You will need the file dwt.res in your build directory and the linker 
option -L/rc:dwt

See also the README.txt in DWT-Win