primitivus, jp: dynamic bridge + fixed D-Bus bridge:

Primitivus and jp can now load the bridge specified in sat.conf, but they are only working with D-Bus so far (need to change all sync calls to async).
    Exit code 3 is used for Bridge init error.

src/bridge/bridge_constructor/constructors/embedded/embedded_template.py

@@ -24,7 +24,7 @@ from sat.core import exceptions
 
 class _Bridge(object):
     def __init__(self):
-        log.info(u"Init embedded bridge...")
+        log.debug(u"Init embedded bridge...")
         self._methods_cbs = {}
         self._signals_cbs = {
             "core": {},