use siteInfo instead of hard code protocol and interwiki

[dan1wang]

related to issue #275

In wtf_wikipedia.js, interwikis and site_map can be retrieved from site info .query.interwikimap

The regexp /\[(https?|news|ftp|mailto|gopher|irc):\/\/[^\]\| ]{4,1500}([\| ].*?)?\]/ is used multiple times. It should be a constant. The allowed protocols can be retrieved from site info.query.protocols

[spencermountain]

if you wanted to move the protocol regexp, pr's welcome