Lock icon does not reflect current state

[ghost]

Steps to reproduce:

1. Log in to NetopeerGUI.
2. Connect to any netoconf server.
3. Switch to 'Startup' datastore.
4. Click 'Lock'.
5. Switch back to 'Running' datastore.

Expected behavior:
When selected running datastore the lock is shown unlocked.

Current behavior:
The lock is shown locked although the running datastore is not locked.

Ideal behavior:
The lock is show unlocked when the datastore is not locked.
The lock is shown locked and green when the datastore is locked and current session is holding the lock.
The lock is show locked and red when the datastore is locked and other session is holding the lock.
The lock icon changes with every LOCK notification (will be implemented in libnetconf soon).

[alexadavid]

lock icon reflects switching between datastores.

Ideal behavior could be implemented after libnetconf LOCK notification, new issue #34 created