Concept,Cologex,Goal: refactor headers

All Cologexes (both Cologexes and CologexSets) are now categorized
as Concepts.
Goals are now also Concepts -- they inherit from Concept as a base
class.

Using Concept as the base class for both Cologex and CologexSet
allows us to treat both cologexes and cologexsets the same way
when comparing in the abstract.

smocore/include/goal.h

@@ -6,7 +6,8 @@
 namespace smo {
 
 class Goal
-: public concepts::Concept {
+: public cologex::Concept
+{
 public:
     Goal() = default;
     ~Goal() = default;
@@ -14,4 +15,4 @@ public:
 
 } // namespace smo
 
-#endif
+#endif // _GOAL_H