Merge remote-tracking branch 'afaerber-or/qom-next-1' into staging

* afaerber-or/qom-next-1:
  target-i386: Use uint32 visitor for [x]level properties
  qdev: Remove PropertyInfo range checking
  qdev: Switch property accessors to fixed-width visitor interfaces
  qdev: Use int32_t container for devfn property
  qapi: Add String visitor coverage to serialization unit tests
  qapi: String visitor, use %f representation for floats
  qapi: Unit tests for visitor-based serialization
  qapi: Add Visitor interfaces for uint*_t and int*_t