Added new icons and new resource change listener

The new icons are still temporary and are just there for a change. They
came from eclipse icons.

The resource change listener that was newly added handles what happens
to the open editors that belong to projects that are closed/deleted. The
listener will close any editors that have had their projects
closed/deleted. This does it by checking if the editor is a
RepoMetadataFormEditor and if it belongs to the project modified.

Signed-off-by: Neil Guzman <nguzman@redhat.com>