Make webactivity compatible with webkit1

If a env variable SUGAR_USE_WEBKIT1 exists,
uses a different module to start the activity using a local webserver,
borrowed from wikipedia activity.
When use webkit1 the web inspector is not enabled, because do not work.

Signed-off-by: Manuel Quiñones <manuq@laptop.org>
Signed-off-by: Gonzalo Odiard <gonzalo@laptop.org>