What is source ?

[Vincent Rivière]

Hello.

My big question :
What is source code ?

The GPL states that if I distribute my projet under GPL, I must distribute 
the sources, too.

Can I generate a Makefile using Makefile.am and automake, then only 
distribute Makefile, claiming that it is the source ?

Similar question with images. My program displays a PNG image in its about 
box. It is a very complex image, I made it with Photoshop and a lot of 
layers. Must I distribute the original PSD image in my source package, or 
will the PNG image be sufficient ?

Vincent