Previously, the proxy class was prepared lazily:
lazy_identity = lazy(identity, int)
lazy_identity(10) # prepared here
lazy_identity(10)
This has a slight advantage that if the lazy doesn't end up getting
used, the preparation work is skipped, however that's not very likely.
Besides this laziness, it is also inconsistent in that the methods which
are wrapped directly (__str__ etc.) are prepared already when __proxy__
is defined, and there is a weird half-initialized state.
This change it so that everything is prepared already on the first line
of the example above.
ae94077e7d