Build-dependency resolution changes in main/{amd64,i386} when adding universe:

 * Provides in libgmpv4-dev introduced ambiguity in many packages (removed Provides)
 * foo2zjs Build-Depends foomatic-filters picking that rather than cups-filters which provides it in main (switched to cups-filters | foomatic-filters)
 * gob2 and krb5 Build-Depends byacc | bison and now pick byacc rather than bison (test-built both successfully)
 * indicator-datetime now picks language-pack-touch-en rather than its fallback of language-pack-en-base (this is how it would be built in CI Train anyway, so it's fine)
 * nlpsolver picks libreoffice-style-elementary as a provider of libreoffice-style or libreoffice-style-default, as well as libreoffice-style-galaxy (appears inconsequential)
 * xaw3d Build-Depends flex-old | flex and now picks flex-old (test-built successfully)
 * several packages now have resolvable build-dependencies at all when they didn't before, as expected