TAB-1564 - Jacques Durand

In spite of all my previous comments on COnformance, the conformance section in this specification is fairly decent ! The conf section job is greatly facilitated by the well worded normative statements with clear assignment to the conformance targets. All my previous comments were tagged "minor" (I think) - they are not critical and should not warrant by themselves a new review cycle. But should be fixed if an opportunity shows up. Several (and maybe all?) could fall under editorial - non material - changes (e.g. the one about renaming "Conformance clause" section and bringing up the functional definition of conformance targets.). Good job to MQTT editors!