Make server deletion asynchronous.

Change-Id: Ie48e77b6741745ab959da7e6006ddaa914787a29
Working on making delete/revert/resize asynchronous.

Change-Id: I58d6589caf8a10089d7ca4b814371c4b98cc7483
Add custom exceptions.

Change-Id: I6c5e46a1905c1d93b7ff1c5e6a68c171451ca8f3
Refactor TaskRunner (return values aren't accessible)

Change-Id: Icfdcbfc870895e9a3eae0aa5b8b9a3771204dc9b