This commit removes border nodes from all the graphical DnD tools. It
also forbids  the DnD of ControlNodes in SequenceNode, and add the
missing mappings for BroadcastSignalAction and ClearAssociationAction in
ConditionalNode.

Bug: #147
Bug: https://github.com/PapyrusSirius/papyrus-web/issues/587


Signed-off-by: Gwendal Daniel <gwendal.daniel@obeosoft.com>