New CRABTask object and JSON information storage

* Implemented new CRABTask object which will in future allow to encampsulate all operation over the CRAB task
* The CRABTask object will read/write a file inside the CRAB jobs diectory where it will store relevant information about the task allowing for "memory" of previous actions and set of parameters
* Current CRABTask writes only the current number of jobs in the task,