Pinning a type to an earlier release works again

A type can be pinned to one of its earlier releases — the record of a specific build — so that its instances keep running that build while newer ones are compiled. From this morning's platform build every such pin was refused, and the page showed an error saying the release was "built against framework 3.0.0.0" while the portal "runs" a long identifier.

The check that refuses builds from another platform generation was reading the wrong field: the release's version number, not the record of which platform build produced its assembly. Those two values can never agree, so no pin could pass. The check now reads the assembly's own build record, and behaves as intended: a release built for another platform generation is still refused with both identities named, while a release from before that record existed is adopted with a note in the log asking for a fresh release, instead of being refused.