Fix wlm-latest tool
The wlm-latest displays the last N images of a given country.
It was broken since the Toolserver migration.
- Update the Database address
- Read the database credentials from the global config
- Update path from toolserver URL to toolforge URL (this could probably be relative link)
- Change year from 2012 to 2017
- Fix image thumb URL
Also add the tool from the index page.