Properly handle URLs passed from command line

Previous, URL arguments passed from the command line were ignored (the
"url_list" attribute in Launcher class was unused). We now pass the list
to start-tor-browser which will open a tab with each URL.

Fix #380.

torbrowser_launcher/launcher.py

@@ -434,6 +434,7 @@ def run(self):
 
         # Run Tor Browser
         cmd = [self.common.paths['tbb']['start'], '--detach']
+        cmd.extend(self.url_list)
         subprocess.call(cmd, cwd=self.common.paths['tbb']['dir_tbb'])
         sys.exit(0)