expanded json config parameters
implemented browse, manage and purchase operation
added operation helper that implements methods to browse vehicles, sell vehicles , etc
added random.go that generates random UIDs, CategoryIDs,...
added cookie_jar.go that implements a place for cookies which is used by http.client
added const.go which holds constants and global variables that are set in the json config
adapted cloudburst to changes of benchmark package
fixed concurrency bug of agents
expanded config of cloudburst config
merge fix