Update of the Autodetecting Build System Demo

I recently wanted to show off my automated dependency generating build system and I noticed that the rpmbuild semantics have subtly changed in the past 6 years, so I uploaded a new version with a fix.

Check it out... I know that these days C/C++ based build systems are uncool,  but just in case - I still think that in spite (or rather because of) its age, this demo has value:

• It shows how to incrementally regenerate dependencies, leading to reliable incremental builds, even after refactorings;
• It shows how you can get a handle on build logs;
• It's a great framework for managing build configurations
• It works well with parallel builds.