symbol comparison and concatenation improvements

[ichthyo]

investigate if the comparison and concatenation operators can be defined more compact and/or expose any performance penalties which could be resolved. Especially, usage of boost/operators should be investigated. But please, verify the impact on the overall compile time of Lumiera, and verify the overall size change, both in debug and release mode. Really build it in those variants and measure the difference. yes, indeed; if it was just about dropping in boost/operators, I would have done it right now