(bug 59223) Page.title(asLink=True) accepts a site object "insite",

where the page is to be shown. This forces to format the link
with family and site code prefix if the "insite" site is different
from Page.site.

The default site is given by -lang and -family option or
from user-config.py if the options are omitted.

Change-Id: I145293e30fc155c50d300caa84af13f7b61b02c2