Sync vs Async APIs

[Alena Prokharchyk <Al...@citrix.com>]

This information is useful to whoever adds new cloudStack APIs.

Starting in 3.0 release, all new APIs (except for list* ones) have to be
added as async. It is done to avoid situations we had in the past - when
the command originally was sync, then due to diff reasons we changed it to
become async. It used to break a lot of setups of the customers doing
integration against our APIs. So we decided to start making at async right
from the start.


When you add a new non-list api, make sure it inherits either from
BaseAsyncCmd or BaseAsyncCreateCmd (when new DB entry is getting created
as a result of API call).

-Alena.