Fix Bug #3606570: Namespace alias error with preloading and page.exists(); this turned out to be a pervasive problem caused by an unannounced (IIRC) breaking change in the API.  Formerly, the API always returned a page title that contained the site's canonical namespace prefix, for pages outside namespace 0; now, it may return a title using a namespace alias instead, as in the case of the gender-specific namespaces identified in the bug report.  Because it is conceivable that other cases of non-canonical namespaces may exist either now or in the future, this is a more general solution that checks all possible namespace aliases before rejecting a page title.
Fix Bug #3606570: Namespace alias error with preloading and page.exists(); this turned out to be a pervasive problem caused by an unannounced (IIRC) breaking change in the API.  Formerly, the API always returned a page title that contained the site's canonical namespace prefix, for pages outside namespace 0; now, it may return a title using a namespace alias instead, as in the case of the gender-specific namespaces identified in the bug report.  Because it is conceivable that other cases of non-canonical namespaces may exist either now or in the future, this is a more general solution that checks all possible namespace aliases before rejecting a page title.

git-svn-id: 9a050473c2aca1e14f53d73349e19b938c2cf203@11195 6a7f98fc-eeb0-4dc1-a6e2-c2c589a08aa6

legoktm/pywikipedia-rewrite