Framework: get_bundle() compatibility update

As install_bundle() now returns a Bundle instead of an integer,
Framework.get_bundle_by_id() now checks if the given object is a Bundle
and calls its get_bundle_id() method if so.
This allows code from 0.4 to be executed without modification.
Copyright and version number update

In prevision to the 0.5 release.
All __version__ and __versioninfo__ members have been update:
__version__: a string representation of the version
__versioninfo__: a tuple representing the version
Documentation update
Version update in the distribution script
Website update: first pass