High: LVM: Merge redhat lvm.sh exclusive activation feature set into heartbeat LVM agent

This patch leaves the original LVM heartbeat functionality
intact while adding these addition features from the redhat agent.

1. Exclusive activation using volume group tags. This feature
allows a volume group to live on shared storage within the cluster
without requiring the use of cLVM for metadata locking.

2. individual logical volume activation for local and cluster
volume groups by using the new 'lvname' option.

3. Better setup validation when the 'exclusive' option is enabled.
This patch validates that when exclusive activation is enabled, either
a cluster volume group is in use with cLVM, or the tags variant is
configured correctly. These new checks also makes it impossible to
enable the exclusive activation for cloned resources.
Fix: deactivate vg fails, loop until deactivated
Low: LVM: Restore LVM agent portability

Thanks to Lars Ellenberg for his review and help on this patch.