Mail Activity Reply Creator

This module aims to facilitate back-and-forth activity assignment
between users by automatically selecting activity creator as the
assignee of the followup activity when using button "Done & schedule
next". Use case:

Mitchell Admin assigns activity "to do" to Marc Demo \> Marc Demo clicks
"done and schedule next" on the activity \> in new activity form,
"assigned to" is set to Mitchell Admin (unless a different default user
is set for the selected activity type).

Furthermore, the module corrects a behavior that can induce user to
assigning a new activity to themselves instead of the previously
selected user. Use case:

Mitchell Admin creates a new activity, selects "Marc Demo" as "assigned
to", but then changes activity type.

In standard behavior "assigned to" is reset to "Mitchell Admin"; with
this module, the user selection is maintained when changing activity
type (unless a different default user is set for the selected activity
type).