Start RPC server with root object defined

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[src/_map.pyx] Remove unused cimport

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[src/_core] Cleanup. Add __repr__ for qb_interface_set_t

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[lib/qb/__init__] main: set top-level object

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>