[online-impl-v2 PATCH 00/10] implement Online property

Hi all, Here are 2nd stab at implementing Online property with various modem drivers. Some more obvious errors (in using g_at_chat_send()) have been fixed. Huawei has been updated after the comment from Marcel. I've dropped support for the Nokia usb stick, according to the spec it does not implement but AT+CFUN=0 and AT+CFUN=1. (Not that I have tested what AT+CFUN=0 does.) Again, I have not been able to test with most modems. All of them might not make sense (if the modem does not support AT+CFUN=4, for instance). There might be some common caveats. E.g., if the modem does to wake up with AT+CFUN=4, it might work with an initial cfun command like "AT+CFUN=1 ; +CFUN=4". At least Calypso requires such an initialization command. I'd appreciate if the people with access to various hardware could test them with the patches here (using test/enable-modem, test/online-modem and test/offline-modem, or, e.g., the connman with "ofono-refactor-v2" and "service-leak" patches). --Pekka