* ir_actions_common should return a deferred : some widgets
do not return a deferred in start, so it could be undefined.
it now is always a deferred.
* add icon for diagram view + breadcrumb support. diagram view
is so rare that it wasn't tested in the client refactoring.
This patch adds an icon for diagram view, and better support for
breadcrumbs
* add warning in debug mode print workflow: when no record is
selected, display a warning instead of failing silently
Géry Debongnie
265ba55646