Sort activities in mailboxes

Bug 1383533: Sort list of activites in in- and outbox from A-Z, leaving 'All
types' at the beginning

Change-Id: I4d6316a142fe223a3444c6f40fc66ce219d9e043
Signed-off-by: Tobias Zeuch <tobias.zeuch@kit.edu>
Merge "Sort activities in mailboxes"