[lib/qb] Import generic modules

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[src/_core.pxd] Define missed fiels: _iface, _name, _objs

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[src/_core.pyx] Define root object.

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[qbee.py] Just import `qb' module with initialised `root' field

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