GUI-1427 added helper method to check role access which also checks cloud type

added helper method to check role access which also checks cloud type

https://eucalyptus.atlassian.net/browse/GUI-1427
I think we had a similar discussion about session values last week. This will be there if it's a euca cloud. If it isn't I was arguing for failing fast since it's a software error we should catch. Seem reasonable?