How to change the skins

Skinning is simple and primitive until the xml module is added.  
For now, simply replace the files in the skin1 folder with new ones. 
The tree-view files are not being used yet, so you can skip those.  
Overall, the simplest thing to do is rename the skin1 folder, then 
call your new folder skin1, and bob's your uncle.  Do a compare to 
make sure all the files in the existing skin1 folder have a 
corresponding file in your new skin folder.  If you change a skin and 
the app won't launch, a missing file is the most likely cause.  
Besides forgetting some, I also had problems with wonky names.  
For example, I did not have a "BtnRaise.png" file.  Instead, I had a 
"BtnRaised.png" file. Close doesn't count.  
The attractiveness of this admittedly crude method is you don't need 
to change the source files or recompile.