Fix cache-incarnation sync

[hglkrijger]

Recently we added code to store the published hostname on disk, in order to detect a hostname change when the agent is not running. When the agent upgrades at runtime across this boundary, we can initiate a hostname change immediately after provisioning. This resets the network adapter, which can cause the manifest or goalstate download to fail.

In some cases, particularly when installing an extension at provision time, this leads to a state where the agent has recorded the Incarnation as n, but ExtensionsConfig.{n}.xml does not yet exist.

This PR contains several updates:

• prevent the network adapter from resetting, and causing the initial failure
• make sure the incarnation is only updated after the cache is stored, in case networking fails for another reason
• reduce the http verbose logging, so debugging is a little easier
• in the case of NSG, ensure we force update the goal state
• update the version to 2.2.5 for publishing
• fixes waagent cannot handle hostname change and dhcp client restart #585

/cc @brendandixon @jinhyunr

[brendandixon]

LGTM