initial support for listing tracked time for all projects

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
use project and report summary only once

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
list times for all projects

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>