Target menu and search criterias moved into a config file
Simplified the function populate_i18n
The form (advanced search) generation moved from javascript to php
I made the code compliant to the roundcube coding guidelines (http://trac.roundcube.net/wiki/Dev_Guidelines)
Bump version to 1.2
Reference plugins.roundcube.net and config step

Also tweek versions to Semantic Versioning format