* Use cached extension version if available
* Pass etag to get_ext_handler_pkgs
* Fix failing stale goal state test
* On a stale goalstate, restart extension handling
Also, simplify the fetch manifest logic which identifies a stale
goal state
* Address first round of PR comments.
* Get rid of stopgap loop for stale goal states
* Use previous pattern to populate ext manifest cache
* Simplify get_ext_manifest
The Agent will monitor for more recent versions and update itself
(without impacting the installed version). If the new Agent fails
(in a very bad way or consistently), the code rolls back to the prior
version.
Signed-off-by: Brendan Dixon <brendand@microsoft.com>
Will Pearson