Differentiate action on wireless disconnection based on disconnection reason.

NM takes one-size-fits-all approach to all wireless errors which leads sometimes to nonsensical behaviour. AFAIU, there may be three main wireless disconnection reason:

1) the network is misconfigured on L2 (e.g. bad outer/inner authentication method of WPA Enterprise). In this case, NM should ask for connection and authentication details again

2) the network is well configured but authentication credentials are wrong (this also applies to "always ask for password scenarios"). NM should keep connection settings as is and ask for new credentials

3) network goes offline. Currently (RHEL's 0.8.1), NM asks for details and if user cancels the dialog, the network is marked as invalid, so NM won't try to connect to it once it becomes reachable again. This is most WTFish behavior of NM, when wireless network gets unreachable, NM should check for it's availability before a reconnect attempt (and connect to it automatically if it goes up again)

Note:
I'm aware that proper handling of 2) is not exactly easy because of wifi handshake crappiness (user having to fill ~ 1-5 values that should be negotiable during handshake) but some of it can already be guessed and other is a good candidate for next 802.11 standards update