Added namespace aliases for thwiki

The namespace aliases "Wikipedia" and "WP" for ns4 and
"H" for ns12 were added in this change.

Bug: 68108
Change-Id: I4127e3f2aa48264f9d1c2c2ccf9b235b65d56f3b
Enable Petition Extension on Labs

Change-Id: I1bb5d3b3db78b1fd0ca84ec4ba363ddcf5b7ef9b
Merge "Added namespace aliases for thwiki"
Merge "Enable Petition Extension on Labs"