Let's try Effect management once more

As usual, I started out intending to do as little as possible
to this to get it working and wound up going overboard.

However, I believe it does allow easy management of the effects
and this will provide a basis for the full blown plugin manager
dialog.

src/effects/ScienFilter.h

@@ -47,7 +47,6 @@ public:
    // EffectIdentInterface implementation
 
    virtual EffectType GetType();
-   //virtual bool EnableFromGetGo(){ return false;};
 
    // EffectClientInterface implementation