Use cmap for getting cluster name
Remove controld dependency in group_join/leave
Auto setup cluster_stack based on what is on disk

This happens only the first time.
mount.ocfs2 reads the stack from the filesystems superblock. If the
stack is not setup, it will modprobe the modules and write the
appropriate stack name to cluster_stack file.
If it is already present, it tries to edit/re-write it, if different.
If it fails, the mount fails.
mkfs.ocfs2: Abort if cluster information is not detected
mkfs: Setup cluster_stack if not setup based on what is set
Auto setup pcmk stack as default if no stack is setup

Note: This changes the default behavior from classic stack to pcmk