Added support for the clips engine in engines.mk
Added the clips engine to configure.engines
Added support for the CLIPS engine to plugins_table.h
Modified configure.engines so that CLIPS is not built by default
renamed the clips folder to expert-system

This will allow me to maintain scummvm coding guidelines
Updated the path for the expert-system engine
Added a basic engine implementation header for expert-system
Added expert-system.cpp and updated the namespace for the engine