[CMake] Clarification for quoting of parameters for "add_executable()"

[SF Markus Elfring]

> What would you like it to print?

It depends on the syntax interpretation if the passed quoted parameter will be 
processed as a CMake list.

David Cole pointed it out to me that this is not the case if some data are 
enclosed by quotation marks.
http://public.kitware.com/Bug/view.php?id=11677#c24588

If I follow this view here, then I expect the following log display.

=>Alpha.cxx;/home/elfring/Projekte/CMake/Test/11677/source/Zulu.cxx<=
Configuring done
CMake Error at CMakeLists.txt:5 (add_executable):
   Cannot find source file 
"Alpha.cxx;/home/elfring/Projekte/CMake/Test/11677/source/Zulu.cxx".  Tried 
extensions .c .C .c++ .cc .cpp
   .cxx .m .M .mm .h .hh .h++ .hm .hpp .hxx .in .txx

The wording of the error message shows an unchanged input parameter now.

Regards,
Markus