6d28ded562
Use internal templates in getChangeMessageThreadId, and to set the listId headers. These are not admin editable templates (they are not in files), they simply make the code a bit more readable and editable at very little cost since we already support velocity templating in emails. Additionaly, factor out the fromline creation to its own function. Change-Id: I197b239e657e1dd604b07510c4430675f05d84eb