Use the value of the Anaconda ibft flag to set the Blivet ibft flag

Previously the Anaconda ibft flag has been ignored by Blivet,
now it is respected, which makes it possible to for example disable
ibft by passing the noibft option to Anaconda during the installation.
Use the value of the Anaconda dmraid flag to set the Blivet dmraid flag
Do not try to activate dmraid sets if the dmraid usage flag is false