Added WCF.Action.Proxy.abortPrevious()
Using auto-aborting in WCF.Search.Base
Fixed aborting of requests
Using WCF.Action.Proxy.abortPrevious() in WCF.ACP.Worker
Merge branch 'master' of github.com:WoltLab/WCF into js/abortRequest
Merge pull request #1204 from MeinAccount/js/abortRequest

Allowing aborting of requests in WCF.Action.Proxy