Make it easier to use the new connection models with Qt4, for testing.
Correctly translate the signal index with Qt4 as well.
Handle Qt4's connection type values here too.
Properly look up sender signals with Qt4.

Ugly, but seems to work.
Show a warning on non-unique connections.
Warn on direct cross-thread connections.
Show the effective connection type on auto connections.
Add client/server communication stubs for the connections extension.
Add context menu to navigate to the sender/receiver objects.
Implement sender/receiver navigation on the server side as well.
Properly share model roles, and don't hardcode context actions.
Bump the protocol version for the new connections extension.