Fix incorrect calls to super-class' __init__ methods.

This was introduced in 2014-05-15Z15:36:22T!h.goebel@crazy-compilers.com.
Add licence-header.
Fix format-errors in print-stmts of media_server_observer util.
Fix: Use official interface for registering namespaces ...

... instead of directly updating a private dict.
Fix: duplicate attribute error in DIDL from fs_storage.

This was caused by explicitly defining xmlns attributes for
namespaces which are already globally registered. I solved this by
registering all namespaces globally and omit any explicitly xmlns
attributes.

SOAP stuff is still todo.
Add proper namespace support to events.