Changes

Improve the reference lifecycle manager

1) The EEFReferenceLifecycleManager has been divided into two separated
classes, the EEFReferenceLifecycleManager for monovalued references and
the EEFMultipleReferencesLifecycleManager for multivalued references
2) The onClickExpression is now properly triggered when the user click
on the table for multivalued references
3) A new variable is available for the onClickExpression of a reference
widget. This variable named onClickEventKind will indicate if the user
has realized a single click or a double click

Change-Id: I7fddd2432c094de063390126c321fe7f74a7fd86
Signed-off-by: Stéphane Bégaudeau <stephane.begaudeau@obeo.fr>

Add a default label for the button widget

Change-Id: I098b963a8a2dad391f412076fff1d8f0758d880b
Signed-off-by: Stéphane Bégaudeau <stephane.begaudeau@obeo.fr>

Fix an issue with truncated button labels

Change-Id: Iccf2d38e86a12909248d4ea0200f1407a1ca2e4f
Signed-off-by: Stéphane Bégaudeau <stephane.begaudeau@obeo.fr>

Fix an issue with the layout of the container of the tab

Since a new composite has been introduced on top of all the groups to
ensure a vertical layout for all the groups, the layout operation needs
to be moved form the group to the tab.

Change-Id: I6e563ef3a17c4a4cb4fd5db3fd3a05edfc179047
Signed-off-by: Stéphane Bégaudeau <stephane.begaudeau@obeo.fr>