Use ScaledResource as type for InstanceGroup members

Use the placeholder type OS::Heat::ScaledResource as the nominal resource
type for resources in an instance group. Use the environment to select the
actual underlying resource type (current AWS::EC2::Instance).

Change-Id: I52252c596fa48e57d927eb78e9d5b7c8261adb3e
Convert Ceilometer Alarms to new Schema format

blueprint property-schema-conversion

Change-Id: Ic44465a1de114ad8165c9d3474f409eb0cc129ad
Merge "Convert Ceilometer Alarms to new Schema format"
Merge "Use ScaledResource as type for InstanceGroup members"