SDKtool: Fix explanation of options in help text.

Change-Id: If5b59896b36e2957c8c634184d75f859b6d1f91a
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
SDKtool: Do not require --debugger "" when using --debuggerid

Change-Id: I9d1c7e5c16d492163d1f6459903096f3b9fb0758
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
SDKtool: Small cleanup

Change-Id: Ic8b88707d6cab9e4bd30db02595017fc6e5b84de
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>