moved checkout intro action into main ngDesign plugin
removed java-gen from constants and project creator
moved findTopFrom in dedicated TopEntitiesLoader class
instantiator now starts by loading bundles referenced by entities
this way, references to constant/typedef defined by bundles can be
successfully resolved
corrected getMapping, was returning too early
treat the absence of mapping as if there was no mapping, and fall back
to delegate lookup in bundle
tricky issue: must copy type returned by typedef
this is because the type is only created once (when the bundle is
instantiated), but is generally used many times (and type is a
containment reference)
guard against NPE in CxPrinter
needed because the printer may be called as code is being written, and
parts of the AST may be null