CID-1251369: not null check changed to null check
CID-1250770 pass through mkdirs() return value
CLOUDSTACK-7880: Creating shared network results in exception
This is due to event publish being wrapped in a transaction, moved it outside of transaction scope.
CLOUDSTACK-7583: Send VmStats to Graphite host when configured

This allows external processing of VmStats information without using
the usage server of CloudStack

Statistics are being send to Graphite using UDP and not TCP.

UDP is used to prevent the management server waiting for TCP timeouts
when the Graphite server is unavailable