import sat/wokkel modules only when making service: when importing some sat/wokkel module, a reactor is installed. This can cause trouble when using sat_pubsub along with other twisted plugin installing a specific reactor (which is the case for SàT backend and Libervia). This patch works around it by importing those modules only when making the service.

include MANIFEST.in sat_pubsub/VERSION
global-include *.py
global-include CHANGELOG COPYING* INSTALL README*
global-include Makefile *.rst *.bat
graft doc
graft db
graft twisted
global-exclude *.un~