[ecf-dev] Additions to org.eclipse.ecf.example.collab.editor

["Ken Gilmer" <kgilmer@xxxxxxxxx>]

I've added more code to the action to retrieve the resource for the
active editor.  I've also added a listener that can be attached to
the editor.  This listener can pass events to a shared container
and retrieve them from other clients.  I see there being two types
of messages:

1. Editor checksum: confirm with a hash that all shared editors have same document (required at start of shared session)
2. Modification event: the string, offset, and lenght of an edit (passing full IDocument is not required)

I think the simplest case would be that a client trying to join a
shared session would first be required to pass a editor content hash
value check, confirming that all editors are in sync.  This would
prevent users from joining a session after edits have been made
however.  Another approach would be to add a thrid message type
which is the full content of the IDocument, asking the user upon join
if they'd like to update the editor with the shared version.

Feedback?

-Ken