WebService request queue

[yuriy-tolstoguzov]

_User story_:
I as user want to add have option to add some web service calls to queue.

_Possible implementation_:

New class: RFWebServiceQueue (queueId, requests, sync/async and so on)
New parameter for RFWebServiceCall attribute: queueId.
In case web service call method contains this parameter, it will be added to queue with specified id instead of direct launching.