Bug 982708: Fix console output for NFC notification commands

This patch adds well-formed error messages to the notification
commands of NFC. Each message is prefixed by 'KO', which signals
errors to the emulator.

Signed-off-by: Thomas Zimmermann <tdz@users.sourceforge.net>
Bug 982708: Rework console interface for NFC notifications

This patch improves the console interface for generating NFC
notifications. The creator functions now return -1 on errors,
and the use of a non-existing active RE or notification type
is detected. Each of these problems produces a weill-formed
error message.

Signed-off-by: Thomas Zimmermann <tdz@users.sourceforge.net>
Bug 982708: Print RF discovery id on calls to NFC's rf_intf_activated notification

The call to NFC's rf_intf_activated notification now returns
the RF discovery id on the console. The id is unique for all
active interfaces and can be used to further manipulate the
connection, such as sending NDEF messages.

Signed-off-by: Thomas Zimmermann <tdz@users.sourceforge.net>