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
CLOUDSTACK-7758: Fixed although api calls are failing, event tab shows them as successful

This closes #29
CLOUDSTACK-7541: Added restriction to not allow custom disk offering with disksize UI doesn't allow but with API we were able to create custom disk offering with disk size which was causing this issue
This closes #28
CLOUDSTACK-7930, CLOUDSTACK-7931: Do not allow to set invalid values for global settings which are of type integer and float

This closes #41
CLOUDSTACK-7932: Fixed wrong semantics for isVmAlive() method in HypervInvestigator

Findbugs will report error on this as it is expecting true/false for Boolean value.
But we have diffrent meaning for null so it is false positive case from findbug

This closes #39
CLOUDSTACK-7929: While creating network offering if one specifies negative value for network rate then we will convert that value to 0 i.e. unlimited

This closes #40