It is simpler to have data split by main model or application like we
already do for models and views. It allows to easily have an overview
of data a module holds.
As we will work on mail related data like adding activities or tweaking
subtypes and templates, having them all in a single file and not lost
between other data helps finding and working with it.
This commit only moves code. No functional change should occur.
Thibault Delavallée
1aa0f9a4db