CRM-9981 Multilingual limitations with more than 2 languages

It's not possible de create several trigger for the same action (create, delete, update) and the same table with mysql 5.1 so it's not an option

The 2 main tables we should concentrate on is civicrm_contribution_page and civicrm_event which have a lot of translatable field mainly of type text.

For the biggest table, we should probably do something like :

• civicrm_ {table} which contains untranslated fields
  - civicrm_{table}

  i18n

  {language} which contains only the translated fields for this language
  - civicrm_{table}_{language}

  which is a view doing a query on the 2 previous table

• triggers to synchronize i18n fields

We this schema, all the changes should be only in :

• CRM/Core/I18n/Schema.php (almost every functions)
• CRM/Core/DAO.php for trigger creation

Maybe we should also add a parameter in the schema xml file to tell that we want this behavior for this table and change GenCode accordingly. Otherwise we need to hardcode the fact that we want this behavior for only specific tables.

I think this issue should resolve itself with the replacement of triggers by doctrine "lifecycle callbacks".