BO : Wording in translation_errors.tpl

Removed duplicate information and simplified strings in order to make life easier for translators.
[*] BO : Wording in translation_form.tpl

Removed duplicate information and simplified strings in order to make life easier for translators.
[*] BO : Wording in translation_mails.tpl

Removed duplicate information and simplified strings in order to make life easier for translators.
[*] BO : Wording in translation_modules.tpl

Removed duplicate information and simplified strings in order to make life easier for translators.
Merge pull request #1572 from xBorderie/translations

[*] BO : Wording in translation form templates.