Mob 226 - WikisApi: support for multiple languages

https://wikia-inc.atlassian.net/browse/MOB-226

Extending WikisApi to allow multiple languages support. Number of languages in one request is limited to 10. 

Sample query from getList method (Using DataMart):
```
SELECT  r.wiki_id AS id,pageviews_7day AS pageviews
FROM report_wiki_recent_pageviews as r,dimension_wikis AS d
WHERE (r.lang IN ('en','es','pl')) AND (r.hub_name = 'Gaming') AND (r.wiki_id = d.wiki_id) AND (d.public = 1)
ORDER BY pageviews desc LIMIT 250
```

Sample query from getByString method:
```
SELECT  city_list.city_id,city_list.city_lang,city_list.city_title,city_variables.cv_value
FROM `city_list`
LEFT JOIN `city_variables` ON ((city_list.city_id = city_variables.cv_city_id AND city_variables.cv_variable_id = 1048)) 
LEFT JOIN `city_cat_mapping` ON ((city_list.city_id = city_cat_mapping.city_id))
WHERE city_list.city_public = '1' AND ((city_list.city_title LIKE '%elders%' OR city_list.city_url LIKE '%elders%' OR city_variables.cv_value LIKE '%elders%')) AND (city_list.city_lang IN ('es','pl','de')) AND city_cat_mapping.cat_id = '2' 
LIMIT 250
```

Please review:
@federico-lox @owend @hakubo @themech  @jacekjursza @idradm @jmarch @moliwikia