globals, stem: explain where torrc options are

Fixes bug #28646. Bugfix v0.4.0

sbws/globals.py

@@ -10,6 +10,8 @@ SPEC_VERSION = '1.2.0'
 
 # This is a dictionary of torrc options we always want to set when launching
 # Tor and that do not depend on any runtime configuration
+# Options that are known at runtime (from configuration file) are added
+# in utils/stem.py launch_tor
 TORRC_STARTING_POINT = {
     # We will find out via the ControlPort and not setting something static
     # means a lower chance of conflict

sbws/util/stem.py

@@ -125,6 +125,7 @@ def launch_tor(conf):
     # Bare minimum things, more or less
     torrc = copy.deepcopy(TORRC_STARTING_POINT)
     # Very important and/or common settings that we don't know until runtime
+    # The rest of the settings are in globals.py
     torrc.update({
         'DataDirectory': conf.getpath('tor', 'datadir'),
         'PidFile': conf.getpath('tor', 'pid'),