Add Etag support and tracelevel for trace.xml

1. Majority of the changes is to factor out the DeploymentStatus related to its own interface from baking it into DeploymentManager.

2. Support Etag for deployment results

3. Trace.xml now sensitive to TraceLevel (default is error).

4. Introduce Progress property to allow live progress on deployment result.

5. Introduce IsTemporary property.  Portal will consume this and not light up Retry button.