[src] Add PXD definition

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[src] Add PXE definition

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[src/_core] Add PXD definition

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[src/_map] Add PXD definition

Signed-off-by: Anton D. Kachalov <mouse@yandex.ru>
[lib/qb/__init__] Add sample usage for map_interface

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