release 4.46

Compatibility issues:
The change mentioned below about @expose now being required by default requires a change in your (server-)code or configuration. Read on for details.

Using @expose(...) on a class to set the instance_mode or/and instance_creator for that
class, also exposes ALL methods of that class. That is an unintended side-effect that will be fixed
in the next Pyro version. You can already fix your code right now to prepare for this. Read on for details.

• @Pyro4.behavior decorator added that should now be used to set instance_mode and instance_creator instead of
  using @Pyro4.expose. You can still use @expose in this release, but its arguments will be removed
  in the next Pyro version. So by then you have to have updated your code or it won't run anymore.
  The fix is simple: replace all occurences of @expose(...) where you set the instance_mode or/and instance_creator
  on your Pyro class, by @behavior(...) -- and add new @expose decorations to the class or the methods
  as required to properly expose them. Also read the next bullet.
• Backwards incompatible behavior change: in the spirit of 'secure by default', it's now required to use @expose
  on things you want to expose via Pyro. This is because the REQUIRE_EXPOSE config item is now True by default.
  The "servers" chapter contains details about this and how you can best approach this upgrade issue.
• blobtransfer example added.
• improved the docs on binary data transfer a bit.
• code now uses set literals instead of old fashioned set([...])
• removed the way outdated 'upgrading from Pyro3' chapter from the documentation.
• Pyro4.util.get_exposed_members now has a cache which speeds up determining object metadata enormously on subsequent connections.
• added paragraph to server chapter in documentation about how to expose classes without changing the source code (such as 3rd party libraries)
• added thirdpartylib example for the above