Andreas Traczyk authored Oct 11, 2017 and Kateryna Kostiuk committed Oct 20, 2017

- Inserts message reception time above incoming/outgoing
  messages with a minumum granularity of 1 minute.

- Formats date based on age.

- Resequences message bubbles based on prioritized time
  labels.

Change-Id: I8151484b9ef348105642adf535689eca5fe103f2
Reviewed-by: Kateryna Kostiuk <kateryna.kostiuk@savoirfairelinux.com>