CLOUDSTACK-7688, CLOUDSTACK-7747: restricted various operations for VM with VM snapshots which breaks VM snapshots.
 Now they are informed that they cannot perform the operation.
 To perform operation they have to remove VM snapshots of VM.
CLOUDSTACK-7767: fixed events are not generated for snapshot creation
CLOUDSTACK-7703, CLOUDSTACK-7752: Fixed deployment planner stuck in infinite loop.
If we create VM with shared service offering and attach disk with local disk offering,
and one of storage pool is full(cannot be allocated) and other is not full then
we are not putting the cluster in avoid list which is causing this infinite loop.

Fixed by putting the cluster in avoid list even if one of the storage pool is full(cannot be allocated)
CLOUDSTACK-7620: Added SNMP MIB file for snmp-alerts plugin