[Cmake] Added feature to source files

[Andy Cedilnik]

Hello!

I just added option of adding to source list files that will be generated
during the build process. The syntax of SOURCE_FILES is compatible
with the old syntax but it has keyword GENERATED to specify files that
will be generated. For example:

SOURCE_FILES ( Project_SRCS
   File1
   File2
   ...
   GENERATED
   GFile1
   GFile2
   ...
   )

So, files File1, File2 and so on, have to exist during CMake stage. Files
GFile1, GFile2, and so on, do not have to exist.

So, using ADD_CUSTOM_COMMAND  and GENERATED in SOURCE_FILES,
you could do something like custom wrapping.

Hope you like it.

				Andy Cedilnik