[cleanup] better class/modules names for a few items
[evol] translation rework: new mechanism to handle translated/untranslated strings, make use of translation parameters, moved I18n class, translations update
[fix] catch problems when splitting the command line, and do not forget to include gettext support for the error messages
[fix] Order: correct silly mistakes
[evol] commands management rework #2: moved command parsing out of the Mail class and created new classes to handle it